SIGUSR1 (Signal 10): Meaning, Exit Code 138 & Fix
SIGUSR1 is Unix signal 10. A process terminated by it reports exit code 138 (128 + 10).
SIGUSR1 has no default kernel meaning; applications assign their own behavior. When it kills a process, the shell reports exit code 138 - the 128 + signal-number convention.
What it means
Whatever the application defines - Node uses it to start the debugger; nginx uses it to reopen logs.
When it happens in CI
- An app-specific control signal was sent.
- A tool repurposed USR1 for reload/dump.
How to handle it
Check the specific tool’s docs for what USR1 does; it is rarely a crash.
Related guides
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