Bug 21575 – Child processes spawned by std.process.spawnProcess accidentally inherit signal masks in parent process

The following code should work successfully but it does not. I confirmed this issue on Linux systems. Here is a link to the code: https://run.dlang.io/is/LgiMdL ```dlang import core.sys.posix.signal; import std.concurrency; import std.datetime : seconds; import std.process; void main() { sigset_t ss; sigemptyset(&ss); sigaddset(&ss, SIGINT); pthread_sigmask(SIG_BLOCK, &ss, null); auto pid = spawnProcess(["sleep", "infinity"]); scope(failure) { kill(pid, SIGKILL); wait(pid); } // kill the spawned process with SIGINT // and send its return code spawn((shared Pid pid) { auto p = cast()pid; kill(p, SIGINT); auto code = wait(p); assert(code < 0); send(ownerTid, code); }, cast(shared)pid); auto received = receiveTimeout(3.seconds, (int) { assert(true); }, ); assert(received); // Line 35 } ``` Expected behavior: It finishes successfully. Actual behavior: It fails with the following message. ``` [email protected](35): Assertion failure ---------------- ??:? _d_assertp [0x55d6e91f5611] onlineapp.d:30 _Dmain [0x55d6e91df832] ``` The reason is that the spawned process inherits the signal handler of the parent process. That is, spawned `sleep infinity` is never stopped with `SIGINT`. In the most cases, it is not intended behavior, I guess.

Sorry, I misunderstood the problem. As shown in the following link, `execve` that is internally called by spawnProcess does not inherit signal handlers but inherits signal masks of the parent process. Inheriting the signal masks is the source of this issue. https://man7.org/linux/man-pages/man7/signal.7.html I fixed the title of this issue.

@tom-tan created dlang/phobos pull request #7766 "Fix issue 21575 - Child processes spawned by std.process.spawnProcess accidentally inherit signal masks in parent process" fixing this issue: - Fix issue 21575 - Child processes spawned by std.process.spawnProcess accidentally inherit signal handlers in parent process - Fix issue 21575 - Child processes spawned by std.process.spawnProcess accidentally inherit signal masks in parent process https://github.com/dlang/phobos/pull/7766

dlang/phobos pull request #7766 "Fix issue 21575 - Child processes spawned by std.process.spawnProcess accidentally inherit signal masks in parent process" was merged into master: - 371e3c8606c54da2c343f570a7571176d178166c by Tomoya Tanjo: Fix issue 21575 - Child processes spawned by std.process.spawnProcess accidentally inherit signal masks in parent process https://github.com/dlang/phobos/pull/7766