see the Config module
The environment variable PERL_MM_OPT may be used to pass the
INSTALLDIRS=vendor option in cases where
is not invoked directly from
Replace <tmp> with the appropriate directory (nominally just tmp)
Please note that dependencies caused by versioned uses and on separately packaged modules are not included in this variable and must be explicitly included.
Debian Perl Policyversion 126.96.36.199, 2012-09-19