It is a manually generated .pm file by the people who are not very much familiar with perl syntax. Hence I suspect that there might be a good chance of mistyping an existing key.
You could get those people into assigning not to %hash, but to @hash, i.e. an array instead. Later in the program, you check @hash whether a "key" occurs twice, before assigning to %hash.

-- 
Ronald Fischer <ynnor@mm.st>

In reply to Re^3: Throw compilation error(or warning) if duplicate keys are present in hash by rovf
in thread Throw compilation error(or warning) if duplicate keys are present in hash by I_love_perl

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