shadow-cljs does not die with parent process

[chenyong]

I'm trying to manage some of build tasks in a Node.js tool. As a result, shadow-cljs lives as a child process in my program, which looks like:

 | |-+= 06446 chen /Applications/iTerm.app/Contents/MacOS/iTerm2 --server /usr/bin/login -fqpl chen /Applications/iTerm.app/Contents/MacOS/iTerm2 --launch_shell
 | | \-+= 06447 root /usr/bin/login -fqpl chen /Applications/iTerm.app/Contents/MacOS/iTerm2 --launch_shell
 | |   \-+= 06448 chen -bash
 | |     \-+= 24048 chen node target/main.js
 | |       |-+- 24093 chen node /usr/local/Cellar/yarn/1.3.2/libexec/bin/yarn.js dev
 | |       | \--- 24094 chen node /Users/chen/work/trace-web/node_modules/.bin/webpack-dev-server --hot --hot-only
 | |       \-+- 31073 chen node ./node_modules/.bin/shadow-cljs watch browser
 | |         \--- 31074 chen /usr/bin/java -Djava.util.logging.config.file=target/shadow-cljs/logging.properties -cp src:/Users/chen/.m2/repository/com/cognitect/transit-clj/0.8.300/transit-clj-0.8.300.jar:/Users/chen/.m2/repository/org/jboss/xnio/xnio-nio/3.3.8.Final/xnio-nio-3.3.8.Final.jar:/Users/chen/.m2/reposit

I can get 31073(PID) in my program and kill it. After that, I found 31074 turned into an orphan process under 00001. Can we make it die as its parent dies?

[thheller]

The problem appears to be child_process.spawnSync. Using cp.spawn combined with an exit handler killing the process seems to work.

One more reason to restructure everything to full async but thats going to take a while.

[hlolli]

Related to this ticket as discussed on Slack, it would make sense to catch the SIGUP/SIGTERM signals and kill Java before calling process.exit(0). Within Emacs I end up with Java zombie processes which may be related to this.

[jiyinyiyong]

Cool.

[jiyinyiyong]

I'm still wondering if the problem is remaining. I tried in my app:

proc = child_process.exec("yarn watch", {});
// "yarn watch" for "shadow-cljs watch client"

// running
proc.kill()
// or
proc.kill("SIGINT")

After killing the process, it's supposed exit. But turned out it's still running.

Not sure what's the problem. But is there any misunderstanding on my side?

---

Tried and it appears to be working with:

node ./node_modules/.bin/shadow-cljs watch client server

So probably yarn scripts has some problem responding to SIGINT events.