Index: src/ccache/execute.cpp
===================================================================
--- src/ccache/execute.cpp.orig 2025-05-31 14:52:32.000000000 +0000
+++ src/ccache/execute.cpp 2025-05-31 15:16:46.000000000 +0000
@@ -297,6 +297,7 @@
 
 // Execute a compiler backend, capturing all output to the given paths the full
 // path to the compiler to run is in argv[0].
+# ifdef HAVE_SPAWN_H
 int
 execute(Context& ctx,
         const char* const* argv,
@@ -372,6 +373,58 @@
 
   return WEXITSTATUS(status);
 }
+# else  // !HAVE_SPAWN_H
+int
+execute(Context& ctx,
+        const char* const* argv,
+        util::Fd&& fd_out,
+        util::Fd&& fd_err)
+{
+  LOG("Executing {}", util::format_argv_for_logging(argv));
+
+  {
+    SignalHandlerBlocker signal_handler_blocker;
+    ctx.compiler_pid = fork();
+  }
+
+  if (ctx.compiler_pid == -1) {
+    throw core::Fatal(FMT("Failed to fork: {}", strerror(errno)));
+  }
+
+  if (ctx.compiler_pid == 0) {
+    // Child.
+    dup2(*fd_out, STDOUT_FILENO);
+    fd_out.close();
+    dup2(*fd_err, STDERR_FILENO);
+    fd_err.close();
+    exit(execv(argv[0], const_cast<char* const*>(argv)));
+  }
+
+  fd_out.close();
+  fd_err.close();
+
+  int status;
+  int result;
+
+  while ((result = waitpid(ctx.compiler_pid, &status, 0)) != ctx.compiler_pid) {
+    if (result == -1 && errno == EINTR) {
+      continue;
+    }
+    throw core::Fatal(FMT("waitpid failed: {}", strerror(errno)));
+  }
+
+  {
+    SignalHandlerBlocker signal_handler_blocker;
+    ctx.compiler_pid = 0;
+  }
+
+  if (WEXITSTATUS(status) == 0 && WIFSIGNALED(status)) {
+    return -1;
+  }
+
+  return WEXITSTATUS(status);
+}
+# endif  // !HAVE_SPAWN_H
 
 void
 execute_noreturn(const char* const* argv, const fs::path& /*temp_dir*/)