CLI crashes with fatal EBADF fd-close-on-GC after successful generation on Node 24 (regression in 2.100.0) #1282

Summary

Since morphir-elm 2.100.0, running morphir make under Node 24 can complete generation successfully and then die with a fatal uncaught exception while the process winds down:

Compiled in DEV mode. Follow the advice at https://elm-lang.org/0.19.1/optimize ...
<anonymous_script>:0

[Error: EBADF: Closing file descriptor 22 on garbage collection failed, close] {
  errno: -9,
  code: 'EBADF',
  syscall: 'close'
}

Node.js v24.19.0

The process exits 1, so any build system driving the CLI reports failure even though the IR was produced. 2.99.0 does not exhibit this under the same Node version.

Environment

• morphir-elm: 2.100.0 (regression; 2.99.0 is fine)
• Node.js: v24.19.0 (linux x64, GitHub Actions ubuntu-latest; also reproduced across reruns)
• Invocation: morphir make via the finos/morphir-scala Mill build against small Elm projects (the unit-test-framework example projects in morphir-scala)

Evidence that it is per-process, not load-related

We first suspected contention between parallel CLI invocations, but the crash reproduces with fully serialized execution (-j 1, one Node process at a time): two independent invocations each crashed the same way in the same run (failing job with serial execution). Across two PRs we saw five consecutive occurrences; earlier occurrences on the same infrastructure were intermittent (example).

Analysis

EBADF on close inside a garbage-collection finalizer means a file descriptor was closed twice: something closes an fd directly while a handle object still owns it, and when that handle is collected its finalizer close fails. Recent Node makes that failure a fatal uncaught exception rather than a warning, which is why the crash lands after all useful work is done. The regression window is whatever changed fd handling between 2.99.0 and 2.100.0 in the CLI path exercised by morphir make.

Impact and downstream workaround

finos/morphir-scala CI was fully blocked and has pinned back to 2.99.0 with a renovate exclusion for exactly 2.100.0 (finos/morphir-scala#963), so a fixed later release will be picked up automatically. Happy to test a candidate fix from a branch or prerelease.