As for your example, the core docs say that if eval completes without error, then $@ is guaranteed to be a null string
Even if that would be true, then
so you can write eval{...}; warn if $@;
doesn't follow.

For the second, you also need $@ to be true if the eval fails. Which doesn't need to be the case.

The problem is end-of-scope effects. eval { } is a block. Leaving the block, whether due to reaching the end, entering a return, or because the code dies, triggers end of scope effects. Which may cause more code to be executed (think DESTROY blocks). Which may clear, or set $@.

This is a known, but hard problem to solve (as one doesn't want to lose information carried in $@). There will be improvements in 5.14, IIRC.

In reply to Re^3: Where did $@ go? by JavaFan
in thread Where did $@ go? by John M. Dlugosz

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