diff --git a/cmd/tools/modules/testing/common.v b/cmd/tools/modules/testing/common.v
index a133baab29..c203a197e3 100644
--- a/cmd/tools/modules/testing/common.v
+++ b/cmd/tools/modules/testing/common.v
@@ -45,6 +45,14 @@ pub const is_node_present = os.execute('node --version').exit_code == 0
 
 pub const is_go_present = os.execute('go version').exit_code == 0
 
+pub const is_ruby_present = os.execute('ruby --version').exit_code == 0
+
+pub const is_python_present = os.execute('python --version').exit_code == 0
+
+pub const is_sqlite3_present = os.execute('sqlite3 --version').exit_code == 0
+
+pub const is_openssl_present = os.execute('openssl --version').exit_code == 0
+
 pub const all_processes = get_all_processes()
 
 pub const header_bytes_to_search_for_module_main = 500
@@ -101,6 +109,7 @@ pub mut:
 	exec_mode ActionMode = .compile // .compile_and_run only for `v test`
 
 	build_environment build_constraint.Environment // see the documentation in v.build_constraint
+	custom_defines    []string                     // for adding custom defines, known only to the individual runners
 }
 
 pub fn (mut ts TestSession) add_failed_cmd(cmd string) {
@@ -219,107 +228,14 @@ pub fn (mut ts TestSession) print_messages() {
 pub fn new_test_session(_vargs string, will_compile bool) TestSession {
 	mut skip_files := []string{}
 	if will_compile {
-		// Skip the call_v_from_* files. They need special instructions for compilation.
-		// Check the README.md for detailed information.
-		skip_files << 'examples/call_v_from_c/v_test_print.v'
-		skip_files << 'examples/call_v_from_c/v_test_math.v'
-		skip_files << 'examples/call_v_from_python/test.v' // the example only makes sense to be compiled, when python is installed
-		skip_files << 'examples/call_v_from_ruby/test.v' // the example only makes sense to be compiled, when ruby is installed
-		// Skip the compilation of the coroutines example for now, since the Photon wrapper
-		// is only available on macos for now, and it is not yet trivial enough to
-		// build/install on the CI:
-		skip_files << 'examples/coroutines/simple_coroutines.v'
-		skip_files << 'examples/coroutines/coroutines_bench.v'
-		$if msvc {
-			skip_files << 'vlib/v/tests/consts/const_comptime_eval_before_vinit_test.v' // _constructor used
-		}
-		$if solaris {
-			skip_files << 'examples/pico/pico.v'
-			skip_files << 'examples/pico/raw_callback.v'
-			skip_files << 'examples/sokol/fonts.v'
-			skip_files << 'examples/sokol/drawing.v'
-		}
-		$if macos {
-			skip_files << 'examples/database/mysql.v'
-			skip_files << 'examples/database/orm.v'
-			skip_files << 'examples/database/psql/customer.v'
-		}
 		$if windows {
-			skip_files << 'examples/vanilla_http_server' // requires epoll
-			skip_files << 'examples/1brc/solution/main.v' // requires mmap
-			skip_files << 'examples/database/mysql.v'
-			skip_files << 'examples/database/orm.v'
-			skip_files << 'examples/smtp/mail.v' // requires OpenSSL
-			skip_files << 'examples/websocket/ping.v' // requires OpenSSL
-			skip_files << 'examples/websocket/client-server/client.v' // requires OpenSSL
-			skip_files << 'examples/websocket/client-server/server.v' // requires OpenSSL
-			skip_files << 'examples/minimal_c_like_program_using_puts.v' // declares its own `main` function, while on windows it needs to be `wWinMain` ... although only for gcc for some reason ¯\_(ツ)_/¯
-			skip_files << 'vlib/v/tests/websocket_logger_interface_should_compile_test.v' // requires OpenSSL
-			skip_files << 'vlib/crypto/ecdsa/ecdsa_test.v' // requires OpenSSL
-			skip_files << 'vlib/crypto/ecdsa/util_test.v' // requires OpenSSL
-			skip_files << 'vlib/crypto/ecdsa/example/ecdsa_seed_test.v' // requires OpenSSL
-			skip_files << 'vlib/crypto/ecdsa/example/ensure_compatibility_with_net_openssl_test.v' // requires OpenSSL
-			$if tinyc {
-				skip_files << 'examples/database/orm.v' // try fix it
-			}
-		}
-		$if windows {
-			// TODO: remove when closures on windows are supported...
-			skip_files << 'examples/pendulum-simulation/animation.v'
-			skip_files << 'examples/pendulum-simulation/full.v'
-			skip_files << 'examples/pendulum-simulation/parallel.v'
-			skip_files << 'examples/pendulum-simulation/parallel_with_iw.v'
-			skip_files << 'examples/pendulum-simulation/sequential.v'
-			if github_job == 'tcc-windows' {
-				// TODO: fix these by adding declarations for the missing functions in the prebuilt tcc
-				skip_files << 'vlib/net/mbedtls/mbedtls_compiles_test.v'
-				skip_files << 'vlib/net/ssl/ssl_compiles_test.v'
-			}
+			skip_files << 'examples/vanilla_http_server' // requires epoll // TODO: find a way to support `// vtest build:` for project folders too...
 		}
 		if runner_os != 'Linux' || !github_job.starts_with('tcc-') {
 			if !os.exists('/usr/local/include/wkhtmltox/pdf.h') {
 				skip_files << 'examples/c_interop_wkhtmltopdf.v' // needs installation of wkhtmltopdf from https://github.com/wkhtmltopdf/packaging/releases
 			}
-			skip_files << 'vlib/vweb/vweb_app_test.v' // imports the `sqlite` module, which in turn includes `sqlite3.h`
-			skip_files << 'vlib/veb/tests/veb_app_test.v' // imports the `sqlite` module, which in turn includes `sqlite3.h`
 		}
-		$if !macos {
-			skip_files << 'examples/macos_tray/tray.v'
-		}
-		if github_job == 'docker-ubuntu-musl' {
-			skip_files << 'vlib/net/openssl/openssl_compiles_test.c.v'
-			skip_files << 'vlib/crypto/ecdsa/ecdsa_test.v' // requires OpenSSL
-			skip_files << 'vlib/crypto/ecdsa/util_test.v' // requires OpenSSL
-			skip_files << 'vlib/crypto/ecdsa/example/ecdsa_seed_test.v' // requires OpenSSL
-			skip_files << 'vlib/crypto/ecdsa/example/ensure_compatibility_with_net_openssl_test.v' // requires OpenSSL
-			skip_files << 'vlib/x/ttf/ttf_test.v'
-			skip_files << 'vlib/encoding/iconv/iconv_test.v' // needs libiconv to be installed
-		}
-		if github_job == 'sanitize-memory-clang' {
-			skip_files << 'vlib/net/openssl/openssl_compiles_test.c.v'
-			skip_files << 'vlib/crypto/ecdsa/ecdsa_test.v' // requires OpenSSL
-			skip_files << 'vlib/crypto/ecdsa/util_test.v' // requires OpenSSL
-			skip_files << 'vlib/crypto/ecdsa/example/ecdsa_seed_test.v' // requires OpenSSL
-			skip_files << 'vlib/crypto/ecdsa/example/ensure_compatibility_with_net_openssl_test.v' // requires OpenSSL
-			// Fails compilation with: `/usr/bin/ld: /lib/x86_64-linux-gnu/libpthread.so.0: error adding symbols: DSO missing from command line`
-			skip_files << 'examples/sokol/sounds/simple_sin_tones.v'
-			skip_files << 'examples/sokol/sounds/simple_sin_tone_using_audio_push.v'
-		}
-		if github_job != 'misc-tooling' {
-			// These examples need .h files that are produced from the supplied .glsl files,
-			// using by the shader compiler tools in https://github.com/floooh/sokol-tools-bin/archive/pre-feb2021-api-changes.tar.gz
-			skip_files << 'examples/sokol/02_cubes_glsl/cube_glsl.v'
-			skip_files << 'examples/sokol/03_march_tracing_glsl/rt_glsl.v'
-			skip_files << 'examples/sokol/04_multi_shader_glsl/rt_glsl.v'
-			skip_files << 'examples/sokol/05_instancing_glsl/rt_glsl.v'
-			skip_files << 'examples/sokol/07_simple_shader_glsl/simple_shader.v'
-			skip_files << 'examples/sokol/08_sdf/sdf.v'
-			// Skip obj_viewer code in the CI
-			skip_files << 'examples/sokol/06_obj_viewer/show_obj.v'
-		}
-		// requires special compilation flags: `-b wasm -os browser`, skip it for now:
-		skip_files << 'examples/wasm/mandelbrot/mandelbrot.wasm.v'
-		skip_files << 'examples/wasm/change_color_by_id/change_color_by_id.wasm.v'
 	}
 	skip_files = skip_files.map(os.abs_path)
 	vargs := _vargs.replace('-progress', '')
@@ -394,25 +310,9 @@ pub fn (mut ts TestSession) test() {
 	mut remaining_files := []string{}
 	for dot_relative_file in ts.files {
 		file := os.real_path(dot_relative_file)
-		$if windows {
-			if file.contains('sqlite') || file.contains('httpbin') {
-				continue
-			}
-		}
-		$if !macos {
-			if file.contains('customer') {
-				continue
-			}
-		}
-		$if msvc {
-			if file.contains('asm') {
-				continue
-			}
-		}
 		if ts.build_tools && dot_relative_file.ends_with('_test.v') {
 			continue
 		}
-
 		// Skip OS-specific tests if we are not running that OS
 		// Special case for android_outside_termux because of its
 		// underscores
@@ -447,7 +347,7 @@ pub fn (mut ts TestSession) test() {
 	pool_of_test_runners.set_shared_context(ts)
 	ts.reporter.worker_threads_start(remaining_files, mut ts)
 
-	ts.build_environment = get_build_environment()
+	ts.setup_build_environment()
 
 	// all the testing happens here:
 	pool_of_test_runners.work_on_pointers(unsafe { remaining_files.pointers() })
@@ -974,8 +874,44 @@ fn get_max_header_len() int {
 	return cols
 }
 
-fn get_build_environment() &build_constraint.Environment {
+// is_started_mysqld is true, when the test runner determines that there is a running mysql server
+pub const is_started_mysqld = find_started_process('mysqld') or { '' }
+
+// is_started_postgres is true, when the test runner determines that there is a running postgres server
+pub const is_started_postgres = find_started_process('postgres') or { '' }
+
+pub fn (mut ts TestSession) setup_build_environment() {
 	facts := os.getenv('VBUILD_FACTS').split_any(',')
-	defines := os.getenv('VBUILD_DEFINES').split_any(',')
-	return build_constraint.new_environment(facts, defines)
+	mut defines := os.getenv('VBUILD_DEFINES').split_any(',')
+	// add the runtime information, that the test runner has already determined by checking once:
+	if is_started_mysqld != '' {
+		defines << 'started_mysqld'
+	}
+	if is_started_postgres != '' {
+		defines << 'started_postgres'
+	}
+	if is_node_present {
+		defines << 'present_node'
+	}
+	if is_python_present {
+		defines << 'present_python'
+	}
+	if is_ruby_present {
+		defines << 'present_ruby'
+	}
+	if is_go_present {
+		defines << 'present_go'
+	}
+	if is_sqlite3_present {
+		defines << 'present_sqlite3'
+	}
+	if is_openssl_present {
+		defines << 'present_openssl'
+	}
+	defines << ts.custom_defines
+	$if trace_vbuild ? {
+		eprintln('>>> testing.get_build_environment facts: ${facts}')
+		eprintln('>>> testing.get_build_environment defines: ${defines}')
+	}
+	ts.build_environment = build_constraint.new_environment(facts, defines)
 }
diff --git a/cmd/tools/vdoc/utils.v b/cmd/tools/vdoc/utils.v
index 7f1d8873cc..2a0493573a 100644
--- a/cmd/tools/vdoc/utils.v
+++ b/cmd/tools/vdoc/utils.v
@@ -73,7 +73,6 @@ fn set_output_type_from_str(format string) OutputType {
 		'md', 'markdown' { .markdown }
 		'json' { .json }
 		'text' { .plaintext }
-		'ansi' { .ansi }
 		else { .ansi }
 	}
 }
diff --git a/cmd/tools/vdoc/vdoc_test.v b/cmd/tools/vdoc/vdoc_test.v
index 6097a811d7..9017892ede 100644
--- a/cmd/tools/vdoc/vdoc_test.v
+++ b/cmd/tools/vdoc/vdoc_test.v
@@ -1,3 +1,4 @@
+// vtest build: !windows
 module main
 
 import os
diff --git a/cmd/tools/vtest-self.v b/cmd/tools/vtest-self.v
index f04abce3a9..278be5d7d6 100644
--- a/cmd/tools/vtest-self.v
+++ b/cmd/tools/vtest-self.v
@@ -97,21 +97,7 @@ const essential_list = [
 	'vlib/v/slow_tests/inout/compiler_test.v',
 	'vlib/x/json2/tests/json2_test.v',
 ]
-const skip_test_files = [
-	'do_not_remove',
-	'cmd/tools/vdoc/vdoc_test.v', // markdown not installed
-	'vlib/context/deadline_test.v', // sometimes blocks
-	'vlib/context/onecontext/onecontext_test.v', // backtrace_symbols is missing
-	'vlib/db/mysql/mysql_orm_test.v', // mysql not installed
-	'vlib/db/mysql/mysql_test.v', // mysql not installed
-	'vlib/db/mysql/prepared_stmt_test.v', // mysql not installed
-	'vlib/db/pg/pg_orm_test.v', // pg not installed
-	'vlib/db/pg/pg_test.v', // pg not installed
-	'vlib/db/pg/pg_double_test.v', // pg not installed
-	'vlib/net/ftp/ftp_test.v', // currently broken
-]
-// These tests are too slow to be run in the CI on each PR/commit
-// in the sanitized modes:
+// These tests are too slow to be run in the CI on each PR/commit in the sanitized modes:
 const skip_fsanitize_too_slow = [
 	'do_not_remove',
 	'vlib/v/compiler_errors_test.v',
@@ -225,33 +211,10 @@ const skip_with_fsanitize_undefined = [
 	'vlib/v/tests/orm_update_test.v',
 	'vlib/v/tests/project_with_cpp_code/compiling_cpp_files_with_a_cplusplus_compiler_test.c.v', // fails compilation with: undefined reference to vtable for __cxxabiv1::__function_type_info'
 ]
-const skip_with_werror = [
-	'do_not_remove',
-	'vlib/v/embed_file/tests/embed_file_test.v',
-]
-const skip_with_asan_compiler = [
-	'do_not_remove',
-]
-const skip_with_msan_compiler = [
-	'do_not_remove',
-]
-const skip_with_ubsan_compiler = [
-	'do_not_remove',
-]
-const skip_on_musl = [
-	'do_not_remove',
-	'vlib/v/slow_tests/profile/profile_test.v',
-	'vlib/gg/draw_fns_api_test.v',
-	'vlib/v/tests/skip_unused/gg_code.vv',
-	'vlib/v/tests/c_struct_with_reserved_field_name_test.v',
-	'vlib/arrays/parallel/parallel_test.v',
-]
 const skip_on_ubuntu_musl = [
 	'do_not_remove',
 	'vlib/arrays/parallel/parallel_test.v',
-	//'vlib/v/gen/js/jsgen_test.v',
-	'vlib/net/http/cookie_test.v',
-	'vlib/net/http/status_test.v',
+	'vlib/builtin/js/array_test.js.v',
 	'vlib/db/sqlite/sqlite_test.v',
 	'vlib/db/sqlite/sqlite_orm_test.v',
 	'vlib/db/sqlite/sqlite_comptime_field_test.v',
@@ -289,92 +252,23 @@ const skip_on_ubuntu_musl = [
 	'vlib/v/tests/orm_create_several_tables_test.v',
 	'vlib/v/tests/orm_update_test.v',
 	'vlib/v/tests/sql_statement_inside_fn_call_test.v',
+	'vlib/v/tests/websocket_logger_interface_should_compile_test.v',
+	'vlib/v/tests/fns/fn_literal_type_test.v',
 	'vlib/clipboard/clipboard_test.v',
 	'vlib/vweb/tests/vweb_test.v',
 	'vlib/vweb/csrf/csrf_test.v',
-	'vlib/net/http/request_test.v',
 	'vlib/vweb/route_test.v',
+	'vlib/net/http/request_test.v',
 	'vlib/net/websocket/websocket_test.v',
 	'vlib/net/http/header_test.v',
 	'vlib/net/http/server_test.v',
 	'vlib/net/http/response_test.v',
-	'vlib/builtin/js/array_test.js.v',
 	'vlib/net/smtp/smtp_test.v',
-	'vlib/v/tests/websocket_logger_interface_should_compile_test.v',
-	'vlib/v/tests/fns/fn_literal_type_test.v',
+	'vlib/net/http/cookie_test.v',
+	'vlib/net/http/status_test.v',
 	'vlib/x/sessions/tests/db_store_test.v',
 	'vlib/veb/tests/veb_app_test.v',
 ]
-const skip_on_linux = [
-	'do_not_remove',
-]
-const skip_on_non_linux = [
-	'do_not_remove',
-]
-const skip_on_windows_msvc = [
-	'do_not_remove',
-	'vlib/v/tests/consts/const_fixed_array_containing_references_to_itself_test.v', // error C2099: initializer is not a constant
-	'vlib/v/tests/consts/const_and_global_with_same_name_test.v', // error C2099: initializer is not a constant
-	'vlib/v/tests/sumtypes/sumtype_as_cast_1_test.v', // error: cannot support compound statement expression ({expr; expr; expr;})
-	'vlib/v/tests/sumtypes/sumtype_as_cast_2_test.v', // error: cannot support compound statement expression ({expr; expr; expr;})
-	'vlib/v/tests/project_with_cpp_code/compiling_cpp_files_with_a_cplusplus_compiler_test.c.v', // TODO
-]
-const skip_on_windows = [
-	'do_not_remove',
-	'vlib/orm/orm_test.v',
-	'vlib/v/tests/orm_sub_struct_test.v',
-	'vlib/v/tests/orm_joined_tables_select_test.v',
-	'vlib/v/tests/orm_handle_error_for_select_from_not_created_table_test.v',
-	'vlib/net/websocket/websocket_test.v',
-	'vlib/net/openssl/openssl_compiles_test.c.v',
-	'vlib/net/http/request_test.v',
-	'vlib/net/smtp/smtp_test.v',
-	'vlib/net/ssl/ssl_compiles_test.v',
-	'vlib/net/mbedtls/mbedtls_compiles_test.v',
-	'vlib/vweb/tests/vweb_test.v',
-	'vlib/vweb/route_test.v',
-	'vlib/sync/many_times_test.v',
-	'vlib/sync/once_test.v',
-	'vlib/v/tests/websocket_logger_interface_should_compile_test.v',
-	'vlib/v/tests/fns/fn_literal_type_test.v',
-]
-const skip_on_non_windows = [
-	'do_not_remove',
-]
-const skip_on_macos = [
-	'do_not_remove',
-]
-const skip_on_non_macos = [
-	'do_not_remove',
-]
-const skip_on_amd64 = [
-	'do_not_remove',
-]
-const skip_on_arm64 = [
-	'do_not_remove',
-]
-const skip_on_non_amd64_or_arm64 = [
-	'do_not_remove',
-	// closures aren't implemented yet:
-	'vlib/v/tests/fns/closure_test.v',
-	// native aren't implemented:
-	'vlib/v/gen/native/tests/native_test.v',
-	'vlib/context/cancel_test.v',
-	'vlib/context/deadline_test.v',
-	'vlib/context/empty_test.v',
-	'vlib/context/value_test.v',
-	'vlib/context/onecontext/onecontext_test.v',
-	'vlib/sync/once_test.v',
-	'vlib/sync/many_times_test.v',
-	'do_not_remove',
-]
-const skip_on_sandboxed_packaging = [
-	'do_not_remove',
-	'vlib/v/slow_tests/inout/compiler_test.v',
-	'vlib/v/gen/native/tests/native_test.v',
-	'vlib/v/compiler_errors_test.v',
-	'vlib/v/gen/c/coutput_test.v',
-]
 
 fn Config.init(vargs []string, targs []string) !Config {
 	mut cfg := Config{}
@@ -455,90 +349,42 @@ fn main() {
 	mut tsession := testing.new_test_session(vargs.join(' '), true)
 	tsession.exec_mode = .compile_and_run
 	tsession.files << all_test_files.filter(!it.contains('testdata' + os.path_separator))
-	tsession.skip_files << skip_test_files
-	if !testing.is_go_present {
-		tsession.skip_files << 'vlib/v/gen/golang/tests/golang_test.v'
-	}
-	testing.find_started_process('mysqld') or {
-		tsession.skip_files << 'vlib/db/mysql/mysql_orm_test.v'
-		tsession.skip_files << 'vlib/db/mysql/mysql_test.v'
-	}
-	testing.find_started_process('postgres') or {
-		tsession.skip_files << 'vlib/db/pg/pg_orm_test.v'
-		tsession.skip_files << 'vlib/db/pg/pg_double_test.v'
-	}
-	$if windows && tinyc {
-		tsession.skip_files << 'vlib/v/tests/project_with_cpp_code/compiling_cpp_files_with_a_cplusplus_compiler_test.c.v'
-	}
 	if !cfg.run_slow_sanitize
 		&& ((cfg.sanitize_undefined || cfg.sanitize_memory || cfg.sanitize_address)
 		|| (cfg.is_msan_compiler || cfg.is_asan_compiler || cfg.is_ubsan_compiler)) {
 		tsession.skip_files << skip_fsanitize_too_slow
+		tsession.custom_defines << 'self_sanitize_too_slow'
 	}
 	if cfg.werror {
-		tsession.skip_files << skip_with_werror
+		tsession.custom_defines << 'self_werror'
 	}
 	if cfg.sanitize_memory {
 		tsession.skip_files << skip_with_fsanitize_memory
+		tsession.custom_defines << 'self_sanitize_memory'
 	}
 	if cfg.sanitize_address {
 		tsession.skip_files << skip_with_fsanitize_address
+		tsession.custom_defines << 'self_sanitize_address'
 	}
 	if cfg.sanitize_undefined {
 		tsession.skip_files << skip_with_fsanitize_undefined
+		tsession.custom_defines << 'self_sanitize_undefined'
 	}
 	if cfg.is_asan_compiler {
-		tsession.skip_files << skip_with_asan_compiler
+		tsession.custom_defines << 'self_asan_compiler'
 	}
 	if cfg.is_msan_compiler {
-		tsession.skip_files << skip_with_msan_compiler
+		tsession.custom_defines << 'self_msan_compiler'
 	}
 	if cfg.is_ubsan_compiler {
-		tsession.skip_files << skip_with_ubsan_compiler
+		tsession.custom_defines << 'self_ubsan_compiler'
 	}
-	if cfg.is_musl_ci {
-		tsession.skip_files << skip_on_musl
+	if cfg.is_sandboxed_packaging {
+		tsession.custom_defines << 'self_sandboxed_packaging'
 	}
 	if cfg.is_ubuntu_musl_ci {
 		tsession.skip_files << skip_on_ubuntu_musl
-	}
-	if cfg.is_sandboxed_packaging {
-		tsession.skip_files << skip_on_sandboxed_packaging
-	}
-	$if !amd64 && !arm64 {
-		tsession.skip_files << skip_on_non_amd64_or_arm64
-	}
-	$if amd64 {
-		tsession.skip_files << skip_on_amd64
-	}
-	$if arm64 {
-		tsession.skip_files << skip_on_arm64
-	}
-	$if !linux {
-		tsession.skip_files << skip_on_non_linux
-	}
-	$if linux {
-		tsession.skip_files << skip_on_linux
-	}
-	$if windows {
-		tsession.skip_files << skip_on_windows
-		$if msvc {
-			tsession.skip_files << skip_on_windows_msvc
-		}
-	}
-	$if !windows {
-		tsession.skip_files << skip_on_non_windows
-	}
-	$if macos {
-		$if arm64 {
-			if cfg.github_job.starts_with('clang-') {
-				tsession.skip_files << 'vlib/net/openssl/openssl_compiles_test.c.v'
-			}
-		}
-		tsession.skip_files << skip_on_macos
-	}
-	$if !macos {
-		tsession.skip_files << skip_on_non_macos
+		tsession.custom_defines << 'self_ubuntu_musl_ci'
 	}
 	// dump(tsession.skip_files)
 	mut unavailable_files := tsession.files.filter(!os.exists(it))
diff --git a/examples/1brc/solution/main.v b/examples/1brc/solution/main.v
index e5dc8e23b7..6b2a7352ce 100644
--- a/examples/1brc/solution/main.v
+++ b/examples/1brc/solution/main.v
@@ -1,3 +1,4 @@
+// vtest build: !windows // requires mmap
 import flag
 import math
 import os
diff --git a/examples/asm.v b/examples/asm.v
index 6a117358b4..2ba1c0e05b 100644
--- a/examples/asm.v
+++ b/examples/asm.v
@@ -1,3 +1,4 @@
+// vtest build: !msvc
 fn main() {
 	a := 100
 	b := 20
diff --git a/examples/call_v_from_c/v_test_math.v b/examples/call_v_from_c/v_test_math.v
index 264a50c77d..041bcd34f7 100644
--- a/examples/call_v_from_c/v_test_math.v
+++ b/examples/call_v_from_c/v_test_math.v
@@ -1,3 +1,4 @@
+// vtest build: false // Check the README.md for detailed information; this file needs special compilation options
 module test_math
 
 import math
diff --git a/examples/call_v_from_c/v_test_print.v b/examples/call_v_from_c/v_test_print.v
index 8e98d97b8c..8eb659780b 100644
--- a/examples/call_v_from_c/v_test_print.v
+++ b/examples/call_v_from_c/v_test_print.v
@@ -1,3 +1,4 @@
+// vtest build: false // Check the README.md for detailed information; this file needs special compilation options
 module test_print
 
 @[export: 'foo']
diff --git a/examples/call_v_from_python/test.v b/examples/call_v_from_python/test.v
index adc0d30f1b..91f79622cd 100644
--- a/examples/call_v_from_python/test.v
+++ b/examples/call_v_from_python/test.v
@@ -1,3 +1,4 @@
+// vtest build: present_python? // the example only makes sense to be compiled, when python is installed
 module test
 
 // Note: compile this with `v -d no_backtrace -shared test.v`
diff --git a/examples/call_v_from_ruby/test.v b/examples/call_v_from_ruby/test.v
index 250791edac..f20007f2d0 100644
--- a/examples/call_v_from_ruby/test.v
+++ b/examples/call_v_from_ruby/test.v
@@ -1,3 +1,4 @@
+// vtest build: present_ruby? // the example only makes sense to be compiled, when ruby is installed
 module test
 
 import math
diff --git a/examples/coroutines/coroutines_bench.v b/examples/coroutines/coroutines_bench.v
index cb98d7f958..7b460510cc 100644
--- a/examples/coroutines/coroutines_bench.v
+++ b/examples/coroutines/coroutines_bench.v
@@ -1,6 +1,5 @@
-// Build with (-gc none, until GC bug is fixed)
-// v -gc none -use-coroutines coroutine_benchs.v
-//
+// vtest build: false // This should be build with: `v -use-coroutines coroutine_benchs.v`
+// Note: the Photon wrapper is not yet trivial enough to build/install on the CI.
 import coroutines
 import time
 import net.http
diff --git a/examples/coroutines/simple_coroutines.v b/examples/coroutines/simple_coroutines.v
index 2629a798a0..fe879cf0cc 100644
--- a/examples/coroutines/simple_coroutines.v
+++ b/examples/coroutines/simple_coroutines.v
@@ -1,6 +1,5 @@
-// Build with
-// v -use-coroutines simple_coroutines.v
-//
+// vtest build: false // This should be build with: v -use-coroutines simple_coroutines.v
+// Note: the Photon wrapper is not yet trivial enough to build/install on the CI.
 import coroutines
 import time
 import os
diff --git a/examples/database/mysql.v b/examples/database/mysql.v
index ccb9564002..8ba007ca6d 100644
--- a/examples/database/mysql.v
+++ b/examples/database/mysql.v
@@ -1,3 +1,4 @@
+// vtest build: !(macos || windows)
 import db.mysql
 
 fn main() {
diff --git a/examples/database/orm.v b/examples/database/orm.v
index 084267db1e..7b4b5c0a4a 100644
--- a/examples/database/orm.v
+++ b/examples/database/orm.v
@@ -1,3 +1,4 @@
+// vtest build: !(macos || windows)
 import os
 import db.sqlite
 import db.mysql
diff --git a/examples/database/psql/customer.v b/examples/database/psql/customer.v
index 517711bf75..c6d2ba74db 100644
--- a/examples/database/psql/customer.v
+++ b/examples/database/psql/customer.v
@@ -1,10 +1,7 @@
+// vtest build: linux
 module main
 
-/*
 import db.pg
-*/
-
-const dash = '----------------------------------------------------------------'
 
 struct Customer {
 	id        int
@@ -13,53 +10,62 @@ struct Customer {
 	country   string
 }
 
+const dash = '----------------------------------------------------------------'
+
 fn main() {
-	/*
-	db := pg.connect(pg.Config{
-		host: 'localhost' //'127.0.0.1'
-		user: 'postgres'
+	db := pg.connect(
+		host:   'localhost' // or '127.0.0.1'
+		user:   'postgres'
 		dbname: 'customerdb'
-	}) or {
-		println('failed to connect')
-		println(err)
+	) or {
+		eprintln('failed to connect, error: ${err}')
 		return
 	}
 
-	nr_customers := db.select count from Customer
-	println('Total customers: $nr_customers')
+	nr_customers := sql db {
+		select count from Customer
+	}!
+	println('Total customers: ${nr_customers}')
 
-	// V syntax can be used to build queries
 	println(dash)
 	bg_country := 'Bulgaria'
-	bg_customers := db.select from Customer where country == bg_country  && id != 2
+	// V syntax can be used to build queries
+	bg_customers := sql db {
+		select from Customer where country == bg_country && id != 2
+	}!
 	for customer in bg_customers {
-		println('$customer.country | $customer.id - $customer.name')
+		println('${customer.country} | ${customer.id} - ${customer.name}')
 	}
 
 	println(dash)
-	ru_customers := db.select from Customer where country == 'Russia'
+	ru_customers := sql db {
+		select from Customer where country == 'Russia'
+	}!
 	for customer in ru_customers {
-		println('$customer.country | $customer.id - $customer.name')
+		println('${customer.country} | ${customer.id} - ${customer.name}')
 	}
 
 	// by adding `limit 1` we tell V that there will be only one object
 	println(dash)
-	existing := db.select from Customer where id == 1 limit 1 or { panic(err) }
-	println('Existing customer name: $existing.name')
+	existing := sql db {
+		select from Customer where id == 1 limit 1
+	}!
+	println('Existing customer name: ${existing}[0].name')
 	println('Existing customer full information:')
 	println(existing)
 
 	println(dash)
 	q := Customer{}
 	// It's easy to handle queries that don't return any data
-	if anon := db.select from Customer where id == 12345 && name == q.name &&
-			nr_orders > q.nr_orders limit 1 {
-		println('Non existing customer name: $anon.name')
-	}
+	_ := sql db {
+		select from Customer where id == 12345 && name == q.name && nr_orders > q.nr_orders limit 1
+	}!
 	// Insert a new customer
 	nc := Customer{
-		name: 'John Doe'
+		name:      'John Doe'
 		nr_orders: 10
 	}
-	db.insert(nc)*/
+	sql db {
+		insert nc into Customer
+	}!
 }
diff --git a/examples/macos_tray/tray.v b/examples/macos_tray/tray.v
index 44e5809f8a..a2becd0f82 100644
--- a/examples/macos_tray/tray.v
+++ b/examples/macos_tray/tray.v
@@ -1,6 +1,5 @@
-// Simple windows-less application that shows a icon button
-// on Mac OS tray.
-//
+// vtest build: macos
+// Simple windows-less application that shows a icon button on Mac OS tray.
 // Tested on Mac OS Monterey (12.3).
 
 module main
diff --git a/examples/minimal_c_like_program_using_puts.v b/examples/minimal_c_like_program_using_puts.v
index 6a4cb2b02a..aa1712162d 100644
--- a/examples/minimal_c_like_program_using_puts.v
+++ b/examples/minimal_c_like_program_using_puts.v
@@ -1,3 +1,4 @@
+// vtest build: !(windows && gcc) // it declares its own `main` function, but on windows && gcc, it needs to be `wWinMain`
 module no_main
 
 // Compile with:
diff --git a/examples/pico/pico.v b/examples/pico/pico.v
index 2dc64cb360..a921a4490a 100644
--- a/examples/pico/pico.v
+++ b/examples/pico/pico.v
@@ -1,3 +1,4 @@
+// vtest build: !solaris
 import json
 import picoev
 import picohttpparser
diff --git a/examples/pico/raw_callback.v b/examples/pico/raw_callback.v
index 5bb4dc878d..da9101f243 100644
--- a/examples/pico/raw_callback.v
+++ b/examples/pico/raw_callback.v
@@ -1,3 +1,4 @@
+// vtest build: !solaris
 module main
 
 import net
diff --git a/examples/smtp/mail.v b/examples/smtp/mail.v
index 2adc8b3efa..118e1b2f3c 100644
--- a/examples/smtp/mail.v
+++ b/examples/smtp/mail.v
@@ -1,3 +1,4 @@
+// vtest build: present_openssl?
 // Creator: nedimf (07/2020)
 import os
 import net.smtp
diff --git a/examples/sokol/02_cubes_glsl/cube_glsl.v b/examples/sokol/02_cubes_glsl/cube_glsl.v
index 2602e4d9c7..968c46e907 100644
--- a/examples/sokol/02_cubes_glsl/cube_glsl.v
+++ b/examples/sokol/02_cubes_glsl/cube_glsl.v
@@ -1,3 +1,4 @@
+// vtest build: misc-tooling // needs .h files that are produced by `v shader`
 /**********************************************************************
 *
 * Sokol 3d cube demo
diff --git a/examples/sokol/03_march_tracing_glsl/rt_glsl.v b/examples/sokol/03_march_tracing_glsl/rt_glsl.v
index 3e1f5adf89..ec557caf1d 100644
--- a/examples/sokol/03_march_tracing_glsl/rt_glsl.v
+++ b/examples/sokol/03_march_tracing_glsl/rt_glsl.v
@@ -1,3 +1,4 @@
+// vtest build: misc-tooling // needs .h files that are produced by `v shader`
 /**********************************************************************
 *
 * Sokol 3d cube demo
diff --git a/examples/sokol/04_multi_shader_glsl/rt_glsl.v b/examples/sokol/04_multi_shader_glsl/rt_glsl.v
index 00674cdf83..9e04cf753f 100644
--- a/examples/sokol/04_multi_shader_glsl/rt_glsl.v
+++ b/examples/sokol/04_multi_shader_glsl/rt_glsl.v
@@ -1,3 +1,4 @@
+// vtest build: misc-tooling // needs .h files that are produced by `v shader`
 /**********************************************************************
 * Sokol 3d cube multishader demo
 * Copyright (c) 2024 Dario Deledda. All rights reserved.
diff --git a/examples/sokol/05_instancing_glsl/rt_glsl.v b/examples/sokol/05_instancing_glsl/rt_glsl.v
index 0ef53aaf6c..cd5488a420 100644
--- a/examples/sokol/05_instancing_glsl/rt_glsl.v
+++ b/examples/sokol/05_instancing_glsl/rt_glsl.v
@@ -1,3 +1,4 @@
+// vtest build: misc-tooling // needs .h files that are produced by `v shader`
 /**********************************************************************
 *
 * Sokol 3d cube multishader demo
diff --git a/examples/sokol/06_obj_viewer/show_obj.v b/examples/sokol/06_obj_viewer/show_obj.v
index 427b610499..d4fdb7d965 100644
--- a/examples/sokol/06_obj_viewer/show_obj.v
+++ b/examples/sokol/06_obj_viewer/show_obj.v
@@ -1,3 +1,4 @@
+// vtest build: misc-tooling // needs .h files that are produced by `v shader`
 /**********************************************************************
 *
 * .obj viewer
diff --git a/examples/sokol/07_simple_shader_glsl/simple_shader.v b/examples/sokol/07_simple_shader_glsl/simple_shader.v
index 5e1346a9f6..44e39f5ed3 100644
--- a/examples/sokol/07_simple_shader_glsl/simple_shader.v
+++ b/examples/sokol/07_simple_shader_glsl/simple_shader.v
@@ -1,5 +1,6 @@
 // Copyright(C) 2022 Lars Pontoppidan. All rights reserved.
 // Use of this source code is governed by an MIT license file distributed with this software package
+// vtest build: misc-tooling // needs .h files that are produced by `v shader`
 module main
 
 // Example shader triangle adapted to V from https://github.com/floooh/sokol-samples/blob/1f2ad36/sapp/triangle-sapp.c
diff --git a/examples/sokol/08_sdf/sdf.v b/examples/sokol/08_sdf/sdf.v
index bc6cbb4de3..ae74426795 100644
--- a/examples/sokol/08_sdf/sdf.v
+++ b/examples/sokol/08_sdf/sdf.v
@@ -1,5 +1,6 @@
 // A Signed Distance Field rendering demo, ported from https://github.com/floooh/sokol-samples/blob/master/sapp/sdf-sapp.c
 // which in turn is based on https://iquilezles.org/articles/mandelbulb/ and https://www.shadertoy.com/view/ltfSWn
+// vtest build: misc-tooling // needs .h files that are produced by `v shader`
 import sokol.sapp
 import sokol.gfx
 
diff --git a/examples/sokol/drawing.v b/examples/sokol/drawing.v
index 1b61dcd968..a31d2c41dc 100644
--- a/examples/sokol/drawing.v
+++ b/examples/sokol/drawing.v
@@ -1,3 +1,4 @@
+// vtest build: !solaris
 import sokol.sapp
 import sokol.gfx
 import sokol.sgl
diff --git a/examples/sokol/fonts.v b/examples/sokol/fonts.v
index ec484c2811..55474ffd57 100644
--- a/examples/sokol/fonts.v
+++ b/examples/sokol/fonts.v
@@ -1,3 +1,4 @@
+// vtest build: !solaris
 import sokol.sapp
 import sokol.gfx
 import sokol.sgl
diff --git a/examples/sokol/sounds/simple_sin_tone_using_audio_push.v b/examples/sokol/sounds/simple_sin_tone_using_audio_push.v
index 99b7fe5e31..e1ca357a5e 100644
--- a/examples/sokol/sounds/simple_sin_tone_using_audio_push.v
+++ b/examples/sokol/sounds/simple_sin_tone_using_audio_push.v
@@ -1,3 +1,4 @@
+// vtest build: !sanitize-memory-clang // Fails compilation with: `ld: /lib/x86_64-linux-gnu/libpthread.so.0: error adding symbols: DSO missing from command line`
 // import log
 import math
 import time
diff --git a/examples/sokol/sounds/simple_sin_tones.v b/examples/sokol/sounds/simple_sin_tones.v
index 671cb05e4b..a6754c0936 100644
--- a/examples/sokol/sounds/simple_sin_tones.v
+++ b/examples/sokol/sounds/simple_sin_tones.v
@@ -1,3 +1,4 @@
+// vtest build: !sanitize-memory-clang // Fails compilation with: `ld: /lib/x86_64-linux-gnu/libpthread.so.0: error adding symbols: DSO missing from command line`
 import time
 import math
 import sokol.audio
diff --git a/examples/wasm/change_color_by_id/change_color_by_id.wasm.v b/examples/wasm/change_color_by_id/change_color_by_id.wasm.v
index 5dd109e9a7..702492ecc7 100644
--- a/examples/wasm/change_color_by_id/change_color_by_id.wasm.v
+++ b/examples/wasm/change_color_by_id/change_color_by_id.wasm.v
@@ -1,3 +1,4 @@
+// vtest build: false // requires special compilation flags: `-b wasm -os browser`
 fn JS.change_color_by_id(ptr u8, len int, color_ptr u8, color_len int)
 
 // `main` must be public!
diff --git a/examples/wasm/mandelbrot/mandelbrot.wasm.v b/examples/wasm/mandelbrot/mandelbrot.wasm.v
index 3390e2788e..bb04735c32 100644
--- a/examples/wasm/mandelbrot/mandelbrot.wasm.v
+++ b/examples/wasm/mandelbrot/mandelbrot.wasm.v
@@ -1,3 +1,4 @@
+// vtest build: false // requires special compilation flags: `-b wasm -os browser`
 fn JS.canvas_x() int
 fn JS.canvas_y() int
 fn JS.setpixel(x int, y int, c f64)
diff --git a/examples/websocket/client-server/client.v b/examples/websocket/client-server/client.v
index 5bedc05fad..49fdf37f7f 100644
--- a/examples/websocket/client-server/client.v
+++ b/examples/websocket/client-server/client.v
@@ -1,3 +1,4 @@
+// vtest build: present_openssl?
 module main
 
 import os
diff --git a/examples/websocket/client-server/server.v b/examples/websocket/client-server/server.v
index 4bf0fb2dbe..bb6de6c158 100644
--- a/examples/websocket/client-server/server.v
+++ b/examples/websocket/client-server/server.v
@@ -1,3 +1,4 @@
+// vtest build: present_openssl?
 module main
 
 import net.websocket
diff --git a/examples/websocket/ping.v b/examples/websocket/ping.v
index 138b3ee3a6..eca823f6e1 100644
--- a/examples/websocket/ping.v
+++ b/examples/websocket/ping.v
@@ -1,3 +1,4 @@
+// vtest build: present_openssl?
 module main
 
 import time
diff --git a/vlib/arrays/parallel/parallel_test.v b/vlib/arrays/parallel/parallel_test.v
index a06637a76c..4ac3c3ad99 100644
--- a/vlib/arrays/parallel/parallel_test.v
+++ b/vlib/arrays/parallel/parallel_test.v
@@ -1,3 +1,4 @@
+// vtest build: !musl?
 import arrays.parallel
 import rand
 import time
diff --git a/vlib/builtin/js/array_test.js.v b/vlib/builtin/js/array_test.js.v
index 19784ee39d..b7f6b0748f 100644
--- a/vlib/builtin/js/array_test.js.v
+++ b/vlib/builtin/js/array_test.js.v
@@ -1,5 +1,6 @@
 // vtest flaky: true
 // vtest retry: 3
+// vtest build: present_node?
 
 fn test_js() {
 	$if js_node {
diff --git a/vlib/builtin/js/int_test.js.v b/vlib/builtin/js/int_test.js.v
index 643e0c2c2b..f775228fad 100644
--- a/vlib/builtin/js/int_test.js.v
+++ b/vlib/builtin/js/int_test.js.v
@@ -1,5 +1,6 @@
 // vtest flaky: true
 // vtest retry: 3
+// vtest build: present_node?
 
 const a = 3
 const u = u64(1)
diff --git a/vlib/builtin/js/map_test.js.v b/vlib/builtin/js/map_test.js.v
index e5842be927..dcccfe3494 100644
--- a/vlib/builtin/js/map_test.js.v
+++ b/vlib/builtin/js/map_test.js.v
@@ -1,5 +1,6 @@
 // vtest flaky: true
 // vtest retry: 3
+// vtest build: present_node?
 import rand
 
 const strings = unique_strings(200, 10)
diff --git a/vlib/builtin/js/string_test.js.v b/vlib/builtin/js/string_test.js.v
index 3cbe571d82..d4f32a1ab1 100644
--- a/vlib/builtin/js/string_test.js.v
+++ b/vlib/builtin/js/string_test.js.v
@@ -1,5 +1,6 @@
 // vtest flaky: true
 // vtest retry: 3
+// vtest build: present_node?
 
 // import strings
 
diff --git a/vlib/context/cancel_test.v b/vlib/context/cancel_test.v
index e4fea68cf2..0c3d45f891 100644
--- a/vlib/context/cancel_test.v
+++ b/vlib/context/cancel_test.v
@@ -1,5 +1,6 @@
 // vtest flaky: true
 // vtest retry: 3
+// vtest build: amd64 || arm64
 import context
 
 // This example demonstrates the use of a cancelable context to prevent a
diff --git a/vlib/context/deadline_test.v b/vlib/context/deadline_test.v
index fd53243a23..4581c73410 100644
--- a/vlib/context/deadline_test.v
+++ b/vlib/context/deadline_test.v
@@ -1,3 +1,4 @@
+// vtest build: false // TODO: it sometimes blocks, investigate why
 import context
 import time
 
diff --git a/vlib/context/empty_test.v b/vlib/context/empty_test.v
index b752d66bba..e4a42fdd23 100644
--- a/vlib/context/empty_test.v
+++ b/vlib/context/empty_test.v
@@ -1,3 +1,4 @@
+// vtest build: amd64 || arm64
 module context
 
 fn test_background() {
diff --git a/vlib/context/onecontext/onecontext_test.v b/vlib/context/onecontext/onecontext_test.v
index f7912a1f48..00ca5bd9c6 100644
--- a/vlib/context/onecontext/onecontext_test.v
+++ b/vlib/context/onecontext/onecontext_test.v
@@ -1,3 +1,4 @@
+// vtest build: false // backtrace_symbols is missing
 module onecontext
 
 import context
diff --git a/vlib/context/value_test.v b/vlib/context/value_test.v
index 687411a917..fc90fe494a 100644
--- a/vlib/context/value_test.v
+++ b/vlib/context/value_test.v
@@ -1,3 +1,4 @@
+// vtest build: amd64 || arm64
 import context
 
 const not_found_value = &Value{
diff --git a/vlib/crypto/ecdsa/ecdsa_test.v b/vlib/crypto/ecdsa/ecdsa_test.v
index 4e7e51a72a..227ebb5771 100644
--- a/vlib/crypto/ecdsa/ecdsa_test.v
+++ b/vlib/crypto/ecdsa/ecdsa_test.v
@@ -1,3 +1,4 @@
+// vtest build: present_openssl? && !(sanitize-memory-clang? || docker-ubuntu-musl?)
 module ecdsa
 
 fn test_ecdsa() {
diff --git a/vlib/crypto/ecdsa/example/ecdsa_seed_test.v b/vlib/crypto/ecdsa/example/ecdsa_seed_test.v
index 72333e04af..230fc7da75 100644
--- a/vlib/crypto/ecdsa/example/ecdsa_seed_test.v
+++ b/vlib/crypto/ecdsa/example/ecdsa_seed_test.v
@@ -1,3 +1,4 @@
+// vtest build: present_openssl? && !(sanitize-memory-clang? || docker-ubuntu-musl?)
 import rand
 import crypto.ecdsa
 import encoding.hex
diff --git a/vlib/crypto/ecdsa/example/ensure_compatibility_with_net_openssl_test.v b/vlib/crypto/ecdsa/example/ensure_compatibility_with_net_openssl_test.v
index 28ef0870b0..a9d16309b2 100644
--- a/vlib/crypto/ecdsa/example/ensure_compatibility_with_net_openssl_test.v
+++ b/vlib/crypto/ecdsa/example/ensure_compatibility_with_net_openssl_test.v
@@ -1,3 +1,4 @@
+// vtest build: present_openssl? && !(sanitize-memory-clang? || docker-ubuntu-musl?)
 import net.openssl
 import crypto.ecdsa
 
diff --git a/vlib/crypto/ecdsa/util_test.v b/vlib/crypto/ecdsa/util_test.v
index 5d67d39e6b..f93cd320a1 100644
--- a/vlib/crypto/ecdsa/util_test.v
+++ b/vlib/crypto/ecdsa/util_test.v
@@ -1,3 +1,4 @@
+// vtest build: present_openssl? && !(sanitize-memory-clang? || docker-ubuntu-musl?)
 module ecdsa
 
 import encoding.hex
diff --git a/vlib/db/mysql/mysql_orm_test.v b/vlib/db/mysql/mysql_orm_test.v
index 6ef11c0355..2bc199fca7 100644
--- a/vlib/db/mysql/mysql_orm_test.v
+++ b/vlib/db/mysql/mysql_orm_test.v
@@ -1,3 +1,4 @@
+// vtest build: started_mysqld?
 import orm
 import db.mysql
 import time
diff --git a/vlib/db/mysql/mysql_test.v b/vlib/db/mysql/mysql_test.v
index 831f9c56f6..b4415b0753 100644
--- a/vlib/db/mysql/mysql_test.v
+++ b/vlib/db/mysql/mysql_test.v
@@ -1,3 +1,4 @@
+// vtest build: started_mysqld?
 import db.mysql
 
 fn test_mysql() {
diff --git a/vlib/db/mysql/prepared_stmt_test.v b/vlib/db/mysql/prepared_stmt_test.v
index 24960b607f..4d99f5acbf 100644
--- a/vlib/db/mysql/prepared_stmt_test.v
+++ b/vlib/db/mysql/prepared_stmt_test.v
@@ -1,3 +1,4 @@
+// vtest build: started_mysqld?
 import db.mysql
 
 fn test_prep() {
diff --git a/vlib/db/pg/pg_double_test.v b/vlib/db/pg/pg_double_test.v
index 9bb49b90a9..dc2623859e 100644
--- a/vlib/db/pg/pg_double_test.v
+++ b/vlib/db/pg/pg_double_test.v
@@ -1,3 +1,4 @@
+// vtest build: started_postgres?
 module main
 
 import db.pg
diff --git a/vlib/db/pg/pg_orm_test.v b/vlib/db/pg/pg_orm_test.v
index eaac68b19c..370213a69f 100644
--- a/vlib/db/pg/pg_orm_test.v
+++ b/vlib/db/pg/pg_orm_test.v
@@ -1,3 +1,4 @@
+// vtest build: started_postgres?
 module main
 
 import orm
diff --git a/vlib/db/pg/pg_test.v b/vlib/db/pg/pg_test.v
index 7af4cdd5d3..081d47a4d7 100644
--- a/vlib/db/pg/pg_test.v
+++ b/vlib/db/pg/pg_test.v
@@ -1,3 +1,4 @@
+// vtest build: started_postgres?
 module main
 
 import db.pg
diff --git a/vlib/db/sqlite/parent_child_test.v b/vlib/db/sqlite/parent_child_test.v
index d164674704..a86ef7582b 100644
--- a/vlib/db/sqlite/parent_child_test.v
+++ b/vlib/db/sqlite/parent_child_test.v
@@ -1,3 +1,4 @@
+// vtest build: present_sqlite3?
 import db.sqlite
 
 struct Parent {
diff --git a/vlib/db/sqlite/sqlite_comptime_field_test.v b/vlib/db/sqlite/sqlite_comptime_field_test.v
index eeb191d07c..40ad635af2 100644
--- a/vlib/db/sqlite/sqlite_comptime_field_test.v
+++ b/vlib/db/sqlite/sqlite_comptime_field_test.v
@@ -1,3 +1,4 @@
+// vtest build: present_sqlite3?
 module main
 
 import db.sqlite
diff --git a/vlib/db/sqlite/sqlite_orm_test.v b/vlib/db/sqlite/sqlite_orm_test.v
index 9a063490bb..82e0ee0956 100644
--- a/vlib/db/sqlite/sqlite_orm_test.v
+++ b/vlib/db/sqlite/sqlite_orm_test.v
@@ -1,3 +1,4 @@
+// vtest build: present_sqlite3?
 import orm
 import db.sqlite
 import time
diff --git a/vlib/db/sqlite/sqlite_test.v b/vlib/db/sqlite/sqlite_test.v
index 436ce50330..827e3daa1d 100644
--- a/vlib/db/sqlite/sqlite_test.v
+++ b/vlib/db/sqlite/sqlite_test.v
@@ -1,3 +1,4 @@
+// vtest build: present_sqlite3?
 import db.sqlite
 
 type Connection = sqlite.DB
diff --git a/vlib/db/sqlite/sqlite_vfs_lowlevel_test.v b/vlib/db/sqlite/sqlite_vfs_lowlevel_test.v
index bb785b1b3b..4bb8988af2 100644
--- a/vlib/db/sqlite/sqlite_vfs_lowlevel_test.v
+++ b/vlib/db/sqlite/sqlite_vfs_lowlevel_test.v
@@ -1,3 +1,4 @@
+// vtest build: present_sqlite3?
 import db.sqlite
 import rand
 
diff --git a/vlib/encoding/iconv/iconv_test.v b/vlib/encoding/iconv/iconv_test.v
index f29294487b..ce6d917012 100644
--- a/vlib/encoding/iconv/iconv_test.v
+++ b/vlib/encoding/iconv/iconv_test.v
@@ -1,3 +1,4 @@
+// vtest build: !docker-ubuntu-musl // needs libiconv to be installed
 import encoding.iconv
 import os
 
diff --git a/vlib/gg/draw_fns_api_test.v b/vlib/gg/draw_fns_api_test.v
index 1ab2948614..da8d1e33df 100644
--- a/vlib/gg/draw_fns_api_test.v
+++ b/vlib/gg/draw_fns_api_test.v
@@ -1,3 +1,4 @@
+// vtest build: !musl?
 import os
 
 fn test_all_samples_can_be_compiled() {
diff --git a/vlib/net/ftp/ftp_test.v b/vlib/net/ftp/ftp_test.v
index bfea567bb3..968f8d991a 100644
--- a/vlib/net/ftp/ftp_test.v
+++ b/vlib/net/ftp/ftp_test.v
@@ -1,3 +1,4 @@
+// vtest build: false // TODO: see if the interface notice can be fixed and the test made to pass with latest V
 import net.ftp
 
 fn test_ftp_client() {
diff --git a/vlib/net/http/request_test.v b/vlib/net/http/request_test.v
index bfc188da74..77cd3a885f 100644
--- a/vlib/net/http/request_test.v
+++ b/vlib/net/http/request_test.v
@@ -1,3 +1,4 @@
+// vtest build: !windows
 module http
 
 import io
diff --git a/vlib/net/mbedtls/mbedtls_compiles_test.v b/vlib/net/mbedtls/mbedtls_compiles_test.v
index 3434ce42f8..3d45974b9e 100644
--- a/vlib/net/mbedtls/mbedtls_compiles_test.v
+++ b/vlib/net/mbedtls/mbedtls_compiles_test.v
@@ -1,3 +1,4 @@
+// vtest build: !(windows && tinyc) // TODO: fix these by adding declarations for the missing functions in the prebuilt tcc
 import net.mbedtls as _
 
 fn test_mbedtls_compiles() {
diff --git a/vlib/net/openssl/openssl_compiles_test.c.v b/vlib/net/openssl/openssl_compiles_test.c.v
index 1284ec15c5..290329c771 100644
--- a/vlib/net/openssl/openssl_compiles_test.c.v
+++ b/vlib/net/openssl/openssl_compiles_test.c.v
@@ -1,3 +1,4 @@
+// vtest build: present_openssl?
 import net.openssl as _
 
 struct Abc {
diff --git a/vlib/net/smtp/smtp_test.v b/vlib/net/smtp/smtp_test.v
index 7ce979a0ef..603a471f99 100644
--- a/vlib/net/smtp/smtp_test.v
+++ b/vlib/net/smtp/smtp_test.v
@@ -1,3 +1,4 @@
+// vtest build: !windows
 import os
 import net.smtp
 import time
diff --git a/vlib/net/ssl/ssl_compiles_test.v b/vlib/net/ssl/ssl_compiles_test.v
index c8bce84b6d..493f1d9901 100644
--- a/vlib/net/ssl/ssl_compiles_test.v
+++ b/vlib/net/ssl/ssl_compiles_test.v
@@ -1,3 +1,4 @@
+// vtest build: present_openssl? && !(windows && tinyc) // TODO: fix these by adding declarations for the missing functions in the prebuilt tcc
 import net.ssl
 
 fn test_ssl_compiles() {
diff --git a/vlib/net/websocket/websocket_test.v b/vlib/net/websocket/websocket_test.v
index bd8496a47f..8211648936 100644
--- a/vlib/net/websocket/websocket_test.v
+++ b/vlib/net/websocket/websocket_test.v
@@ -1,3 +1,4 @@
+// vtest build: !windows
 import os
 import net
 import net.websocket
diff --git a/vlib/orm/orm_test.v b/vlib/orm/orm_test.v
index 9c0aca2000..02b6da3046 100644
--- a/vlib/orm/orm_test.v
+++ b/vlib/orm/orm_test.v
@@ -1,5 +1,6 @@
 // vtest flaky: true
 // vtest retry: 3
+// vtest build: !windows
 // import db.mysql
 // import db.pg
 import time
diff --git a/vlib/os/open_and_read_from_file_test.js.v b/vlib/os/open_and_read_from_file_test.js.v
index cb72a6bb4d..182b7d0a30 100644
--- a/vlib/os/open_and_read_from_file_test.js.v
+++ b/vlib/os/open_and_read_from_file_test.js.v
@@ -1,3 +1,4 @@
+// vtest build: present_node?
 import os
 
 fn test_read_from_file() {
diff --git a/vlib/rand/rand_test.js.v b/vlib/rand/rand_test.js.v
index 8603bbd4a5..675ad8e3b3 100644
--- a/vlib/rand/rand_test.js.v
+++ b/vlib/rand/rand_test.js.v
@@ -1,3 +1,4 @@
+// vtest build: present_node?
 import rand
 
 fn test_string() {
diff --git a/vlib/strings/builder_test.js.v b/vlib/strings/builder_test.js.v
index 92fca34acd..7ea01edad8 100644
--- a/vlib/strings/builder_test.js.v
+++ b/vlib/strings/builder_test.js.v
@@ -1,3 +1,4 @@
+// vtest build: present_node?
 import strings
 
 type MyInt = int
diff --git a/vlib/strings/similarity_test.js.v b/vlib/strings/similarity_test.js.v
index 965da450cd..cd2046fdf1 100644
--- a/vlib/strings/similarity_test.js.v
+++ b/vlib/strings/similarity_test.js.v
@@ -1,3 +1,4 @@
+// vtest build: present_node?
 import strings
 
 fn test_levenshtein_distance() {
diff --git a/vlib/strings/strings_test.js.v b/vlib/strings/strings_test.js.v
index ff5ddf504a..72cf6a98e6 100644
--- a/vlib/strings/strings_test.js.v
+++ b/vlib/strings/strings_test.js.v
@@ -1,3 +1,4 @@
+// vtest build: present_node?
 import strings
 
 fn test_repeat() {
diff --git a/vlib/strings/textscanner/textscanner_test.js.v b/vlib/strings/textscanner/textscanner_test.js.v
index ef91b42a44..0ebce6f7b5 100644
--- a/vlib/strings/textscanner/textscanner_test.js.v
+++ b/vlib/strings/textscanner/textscanner_test.js.v
@@ -1,3 +1,4 @@
+// vtest build: present_node?
 import strings.textscanner
 
 fn test_remaining() {
diff --git a/vlib/sync/many_times_test.v b/vlib/sync/many_times_test.v
index 7853b551d9..05c39d2560 100644
--- a/vlib/sync/many_times_test.v
+++ b/vlib/sync/many_times_test.v
@@ -1,3 +1,4 @@
+// vtest build: !windows && (amd64 || arm64)
 import sync
 
 struct Counter {
diff --git a/vlib/sync/once_test.v b/vlib/sync/once_test.v
index 62bf3aa30e..6299ed50d3 100644
--- a/vlib/sync/once_test.v
+++ b/vlib/sync/once_test.v
@@ -1,3 +1,4 @@
+// vtest build: !windows && (amd64 || arm64)
 import sync
 
 struct One {
diff --git a/vlib/v/compiler_errors_test.v b/vlib/v/compiler_errors_test.v
index ef0d7d4918..8614564413 100644
--- a/vlib/v/compiler_errors_test.v
+++ b/vlib/v/compiler_errors_test.v
@@ -1,3 +1,4 @@
+// vtest build: !self_sandboxed_packaging?
 import os
 import term
 import v.util.diff
diff --git a/vlib/v/embed_file/tests/embed_file_test.v b/vlib/v/embed_file/tests/embed_file_test.v
index 5dc121dfef..dd4c8e5fcf 100644
--- a/vlib/v/embed_file/tests/embed_file_test.v
+++ b/vlib/v/embed_file/tests/embed_file_test.v
@@ -1,4 +1,5 @@
 const const_file = $embed_file('v.png')
+// vtest build: !self_werror?
 
 const src = $embed_file('embed_file_test.v').to_string()
 
diff --git a/vlib/v/gen/c/coutput_test.v b/vlib/v/gen/c/coutput_test.v
index ed9907a3a1..5136ad01b9 100644
--- a/vlib/v/gen/c/coutput_test.v
+++ b/vlib/v/gen/c/coutput_test.v
@@ -1,3 +1,4 @@
+// vtest build: !self_sandboxed_packaging?
 import os
 import time
 import term
diff --git a/vlib/v/gen/golang/tests/golang_test.v b/vlib/v/gen/golang/tests/golang_test.v
index 9a8a1dcac9..c3964bb513 100644
--- a/vlib/v/gen/golang/tests/golang_test.v
+++ b/vlib/v/gen/golang/tests/golang_test.v
@@ -1,3 +1,4 @@
+// vtest build: present_go?
 import os
 import benchmark
 import term
diff --git a/vlib/v/gen/native/tests/native_test.v b/vlib/v/gen/native/tests/native_test.v
index f10ff80701..41905bf66f 100644
--- a/vlib/v/gen/native/tests/native_test.v
+++ b/vlib/v/gen/native/tests/native_test.v
@@ -1,3 +1,4 @@
+// vtest build: (amd64 || arm64) && !self_sandboxed_packaging?
 import os
 import time
 import benchmark
diff --git a/vlib/v/slow_tests/assembly/asm_test.amd64.v b/vlib/v/slow_tests/assembly/asm_test.amd64.v
index 02520e68bb..748984ef70 100644
--- a/vlib/v/slow_tests/assembly/asm_test.amd64.v
+++ b/vlib/v/slow_tests/assembly/asm_test.amd64.v
@@ -1,3 +1,4 @@
+// vtest build: !msvc
 import v.slow_tests.assembly.util
 
 fn test_inline_asm() {
diff --git a/vlib/v/slow_tests/assembly/asm_test.i386.v b/vlib/v/slow_tests/assembly/asm_test.i386.v
index 61f93bfc31..a715bb801b 100644
--- a/vlib/v/slow_tests/assembly/asm_test.i386.v
+++ b/vlib/v/slow_tests/assembly/asm_test.i386.v
@@ -1,3 +1,4 @@
+// vtest build: !msvc
 import v.tests.assembly.util
 
 fn test_inline_asm() {
diff --git a/vlib/v/slow_tests/inout/compiler_test.v b/vlib/v/slow_tests/inout/compiler_test.v
index d96b588ee2..aece072a35 100644
--- a/vlib/v/slow_tests/inout/compiler_test.v
+++ b/vlib/v/slow_tests/inout/compiler_test.v
@@ -1,3 +1,4 @@
+// vtest build: !self_sandboxed_packaging?
 // .out file:
 // To test a panic, remove everything after the long `===` line
 // You can also remove the line with 'line:' e.g. for a builtin fn
diff --git a/vlib/v/slow_tests/profile/profile_test.v b/vlib/v/slow_tests/profile/profile_test.v
index d327e6fb7f..3b9c228f80 100644
--- a/vlib/v/slow_tests/profile/profile_test.v
+++ b/vlib/v/slow_tests/profile/profile_test.v
@@ -1,3 +1,4 @@
+// vtest build: !musl?
 import os
 import time
 
diff --git a/vlib/v/tests/c_struct_with_reserved_field_name_test.v b/vlib/v/tests/c_struct_with_reserved_field_name_test.v
index 814a786292..9c3facea15 100644
--- a/vlib/v/tests/c_struct_with_reserved_field_name_test.v
+++ b/vlib/v/tests/c_struct_with_reserved_field_name_test.v
@@ -1,3 +1,4 @@
+// vtest build: !musl?
 import gg
 import gx
 
diff --git a/vlib/v/tests/casts/cast_test.js.v b/vlib/v/tests/casts/cast_test.js.v
index 3a0e2a5607..fcb0ad88ee 100644
--- a/vlib/v/tests/casts/cast_test.js.v
+++ b/vlib/v/tests/casts/cast_test.js.v
@@ -1,3 +1,4 @@
+// vtest build: present_node?
 fn JS.Math.pow(JS.Number, JS.Number) JS.Number
 
 fn test_js_prim_cast() {
diff --git a/vlib/v/tests/consts/const_and_global_with_same_name_test.v b/vlib/v/tests/consts/const_and_global_with_same_name_test.v
index ccade3f4b5..3dda631d4d 100644
--- a/vlib/v/tests/consts/const_and_global_with_same_name_test.v
+++ b/vlib/v/tests/consts/const_and_global_with_same_name_test.v
@@ -1,3 +1,4 @@
+// vtest build: !msvc // error C2099: initializer is not a constant
 @[has_globals]
 module main
 
diff --git a/vlib/v/tests/consts/const_comptime_eval_before_vinit_test.v b/vlib/v/tests/consts/const_comptime_eval_before_vinit_test.v
index 780e145944..6f17b50e90 100644
--- a/vlib/v/tests/consts/const_comptime_eval_before_vinit_test.v
+++ b/vlib/v/tests/consts/const_comptime_eval_before_vinit_test.v
@@ -1,3 +1,4 @@
+// vtest build: !msvc  // _constructor used
 // Note: the names are deliberately prefixed with zzz_, so that searching
 // for that in the generated C code is easier. Do not rename the consts.
 const zzz_an_i8_const = i8(0x28)
diff --git a/vlib/v/tests/consts/const_fixed_array_containing_references_to_itself_test.v b/vlib/v/tests/consts/const_fixed_array_containing_references_to_itself_test.v
index 18d7566572..12692692ef 100644
--- a/vlib/v/tests/consts/const_fixed_array_containing_references_to_itself_test.v
+++ b/vlib/v/tests/consts/const_fixed_array_containing_references_to_itself_test.v
@@ -1,3 +1,4 @@
+// vtest build: !msvc // error C2099: initializer is not a constant
 struct Abc {
 	prev &Abc = unsafe { nil }
 }
diff --git a/vlib/v/tests/fns/closure_test.v b/vlib/v/tests/fns/closure_test.v
index d5d75b0c09..2278c0eb35 100644
--- a/vlib/v/tests/fns/closure_test.v
+++ b/vlib/v/tests/fns/closure_test.v
@@ -1,3 +1,4 @@
+// vtest build: amd64 || arm64 // closures aren't implemented yet
 fn test_decl_assignment() {
 	my_var := 12
 	c1 := fn [my_var] () int {
diff --git a/vlib/v/tests/fns/fn_literal_type_test.v b/vlib/v/tests/fns/fn_literal_type_test.v
index 10a9c09347..55cec49d3e 100644
--- a/vlib/v/tests/fns/fn_literal_type_test.v
+++ b/vlib/v/tests/fns/fn_literal_type_test.v
@@ -1,3 +1,4 @@
+// vtest build: !windows
 import db.sqlite
 
 @[table: 'Users']
diff --git a/vlib/v/tests/interop_test.js.v b/vlib/v/tests/interop_test.js.v
index 6530b361cd..7372c27583 100644
--- a/vlib/v/tests/interop_test.js.v
+++ b/vlib/v/tests/interop_test.js.v
@@ -1,3 +1,4 @@
+// vtest build: present_node?
 // Not real external functions, so we won't call them
 // We just want to make sure they compile
 
diff --git a/vlib/v/tests/orm_handle_error_for_select_from_not_created_table_test.v b/vlib/v/tests/orm_handle_error_for_select_from_not_created_table_test.v
index 036f756a1a..72f0aa6b6b 100644
--- a/vlib/v/tests/orm_handle_error_for_select_from_not_created_table_test.v
+++ b/vlib/v/tests/orm_handle_error_for_select_from_not_created_table_test.v
@@ -1,3 +1,4 @@
+// vtest build: present_sqlite3?
 import db.sqlite
 
 struct User {
diff --git a/vlib/v/tests/orm_joined_tables_select_test.v b/vlib/v/tests/orm_joined_tables_select_test.v
index 0ab446178f..0c3612c4f5 100644
--- a/vlib/v/tests/orm_joined_tables_select_test.v
+++ b/vlib/v/tests/orm_joined_tables_select_test.v
@@ -1,3 +1,4 @@
+// vtest build: present_sqlite3?
 import db.sqlite
 
 struct VieterDb {
diff --git a/vlib/v/tests/orm_sub_struct_test.v b/vlib/v/tests/orm_sub_struct_test.v
index 0b0769e0c8..2847e64f2e 100644
--- a/vlib/v/tests/orm_sub_struct_test.v
+++ b/vlib/v/tests/orm_sub_struct_test.v
@@ -1,3 +1,4 @@
+// vtest build: present_sqlite3?
 import db.sqlite
 
 struct Upper {
diff --git a/vlib/v/tests/project_with_cpp_code/compiling_cpp_files_with_a_cplusplus_compiler_test.c.v b/vlib/v/tests/project_with_cpp_code/compiling_cpp_files_with_a_cplusplus_compiler_test.c.v
index 13a341f8e2..69b8469089 100644
--- a/vlib/v/tests/project_with_cpp_code/compiling_cpp_files_with_a_cplusplus_compiler_test.c.v
+++ b/vlib/v/tests/project_with_cpp_code/compiling_cpp_files_with_a_cplusplus_compiler_test.c.v
@@ -1,3 +1,4 @@
+// vtest build: !(windows && tinyc|| msvc) // TODO
 module main
 
 #flag @VMODROOT/implementation.o
diff --git a/vlib/v/tests/skip_unused/gg_code.vv b/vlib/v/tests/skip_unused/gg_code.vv
index 6d32bc0214..89e93e7827 100644
--- a/vlib/v/tests/skip_unused/gg_code.vv
+++ b/vlib/v/tests/skip_unused/gg_code.vv
@@ -1,3 +1,4 @@
+// vtest build: !musl?
 module main
 
 import gg
diff --git a/vlib/v/tests/sumtypes/sumtype_as_cast_1_test.v b/vlib/v/tests/sumtypes/sumtype_as_cast_1_test.v
index a0a7569111..ed6c20f64d 100644
--- a/vlib/v/tests/sumtypes/sumtype_as_cast_1_test.v
+++ b/vlib/v/tests/sumtypes/sumtype_as_cast_1_test.v
@@ -1,3 +1,4 @@
+// vtest build: !msvc // error: cannot support compound statement expression ({expr; expr; expr;})
 type Sum = int | string
 
 struct Count {
diff --git a/vlib/v/tests/sumtypes/sumtype_as_cast_2_test.v b/vlib/v/tests/sumtypes/sumtype_as_cast_2_test.v
index de002006d6..374eff9240 100644
--- a/vlib/v/tests/sumtypes/sumtype_as_cast_2_test.v
+++ b/vlib/v/tests/sumtypes/sumtype_as_cast_2_test.v
@@ -1,3 +1,4 @@
+// vtest build: !msvc // error: cannot support compound statement expression ({expr; expr; expr;})
 type Numbers = int | string
 
 struct Values {
diff --git a/vlib/v/tests/websocket_logger_interface_should_compile_test.v b/vlib/v/tests/websocket_logger_interface_should_compile_test.v
index 8ae90654eb..5658e45086 100644
--- a/vlib/v/tests/websocket_logger_interface_should_compile_test.v
+++ b/vlib/v/tests/websocket_logger_interface_should_compile_test.v
@@ -1,3 +1,4 @@
+// vtest build: !windows && present_openssl?
 import net.websocket as ws
 
 pub type RawMessage = ws.Message
diff --git a/vlib/veb/tests/veb_app_test.v b/vlib/veb/tests/veb_app_test.v
index ca9b76c04b..12d265c424 100644
--- a/vlib/veb/tests/veb_app_test.v
+++ b/vlib/veb/tests/veb_app_test.v
@@ -1,3 +1,4 @@
+// vtest build: present_sqlite3? // imports db.sqlite
 import veb
 import time
 import db.sqlite
diff --git a/vlib/vweb/route_test.v b/vlib/vweb/route_test.v
index 00b68988d4..1ad4fc3db6 100644
--- a/vlib/vweb/route_test.v
+++ b/vlib/vweb/route_test.v
@@ -1,3 +1,4 @@
+// vtest build: !windows
 module vweb
 
 struct RoutePair {
diff --git a/vlib/vweb/tests/vweb_test.v b/vlib/vweb/tests/vweb_test.v
index bdb05d9a36..fc40cebbfb 100644
--- a/vlib/vweb/tests/vweb_test.v
+++ b/vlib/vweb/tests/vweb_test.v
@@ -1,3 +1,4 @@
+// vtest build: !windows
 import io
 import json
 import time
diff --git a/vlib/vweb/vweb_app_test.v b/vlib/vweb/vweb_app_test.v
index 41e7c0da68..432dabf4fb 100644
--- a/vlib/vweb/vweb_app_test.v
+++ b/vlib/vweb/vweb_app_test.v
@@ -1,3 +1,4 @@
+// vtest build: present_sqlite3? // imports db.sqlite
 module main
 
 import vweb
diff --git a/vlib/x/ttf/ttf_test.v b/vlib/x/ttf/ttf_test.v
index 4f5c4f36f9..bc330f4d74 100644
--- a/vlib/x/ttf/ttf_test.v
+++ b/vlib/x/ttf/ttf_test.v
@@ -1,3 +1,4 @@
+// vtest build: !docker-ubuntu-musl
 import x.ttf
 import os
 import strings