Have you meant 
av_push(PL_inc, newSVpv("/opt/myapp/lib", 15));

[download]
However, it can only be called after perl_parse() So maybe I'm on wrong way.

In reply to Re^2: How @INC can be managed from c code? by DrMoisha
in thread How @INC can be managed from c code? by DrMoisha

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