It is localizing $SIG{ALRM} that sets the signal handler to SIG_DFL. Presumably a side effect of $SIG{ALRM} being set to undef when it is localized.

That is stunningly unfriendly. Particularly as localisation is suggested in the documentation (perlipc).

Looks like a bug to me... or at least in need of a serious (additional) caveat in the documentation ?

In reply to Re^2: Setting signal handlers considered unsafe? by gone2015
in thread Setting signal handlers considered unsafe? by gnosek

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