test timeouts

CLAUDE.md

@@ -14,4 +14,7 @@
 - debug printfs: add printfs only when debugging a specific issue; when done
   debugging, remove them (or comment them if you may find them useful later). I
   prefer committing code only when `zig build` returns no output.
+- Always complete all tasks before stopping. Do not stop to ask for
+  confirmation mid-task. If you have remaining work, continue without waiting
+  for input.
 - remember: **mechanical copy** when porting existing stuff, no new creativity.

README.md

@@ -18,7 +18,12 @@ This is written with help from LLM:
 
 Quick test:
 
-    zig build fmt && zig build
+    zig build test
+
+Full test with all supported compilers and valgrind (run before commit,
+takes a while):
+
+    zig build fmt && zig build -Dvalgrind
 
 # Debugging tips
 

build.zig

@@ -48,6 +48,7 @@ pub fn build(b: *std.Build) !void {
     const cc = b.option([]const u8, "cc", "C compiler") orelse "zig";
     const no_exec = b.option(bool, "no-exec", "Compile test binary without running it") orelse false;
     const valgrind = b.option(bool, "valgrind", "Run tests under valgrind") orelse false;
+    const test_timeout = b.option([]const u8, "test-timeout", "Test execution timeout (default: 10s, or 60s with valgrind)");
 
     const target = blk: {
         var query = b.standardTargetOptionsQueryOnly(.{});
@@ -61,7 +62,7 @@ pub fn build(b: *std.Build) !void {
     };
 
     const test_step = b.step("test", "Run unit tests");
-    addTestStep(b, test_step, target, optimize, cc, no_exec, valgrind);
+    addTestStep(b, test_step, target, optimize, cc, no_exec, valgrind, test_timeout);
 
     const fmt_step = b.step("fmt", "clang-format");
     const clang_format = b.addSystemCommand(&.{ "clang-format", "-i" });
@@ -117,7 +118,7 @@ pub fn build(b: *std.Build) !void {
     all_step.dependOn(&fmt_check.step);
 
     for (compilers) |compiler| {
-        addTestStep(b, all_step, target, optimize, compiler, false, valgrind);
+        addTestStep(b, all_step, target, optimize, compiler, false, valgrind, test_timeout);
     }
 
     b.default_step = all_step;
@@ -131,6 +132,7 @@ fn addTestStep(
     cc: []const u8,
     no_exec: bool,
     valgrind: bool,
+    test_timeout: ?[]const u8,
 ) void {
     const test_mod = b.createModule(.{
         .root_source_file = b.path("test_all.zig"),
@@ -164,8 +166,11 @@ fn addTestStep(
         .use_llvm = false,
         .use_lld = false,
     });
+    const timeout = test_timeout orelse if (valgrind) "300" else "10";
     if (valgrind) {
         test_exe.setExecCmd(&.{
+            "timeout",
+            timeout,
             "valgrind",
             "--error-exitcode=2",
             "--leak-check=full",
@@ -174,6 +179,8 @@ fn addTestStep(
             "--track-fds=yes",
             null,
         });
+    } else {
+        test_exe.setExecCmd(&.{ "timeout", timeout, null });
     }
     if (no_exec) {
         const install = b.addInstallArtifact(test_exe, .{});