1 This is in-house developed patch reported at

     2 https://rt.perl.org/Ticket/Display.html?id=121972

     3 

     4 Expectation is that future perl versions will contain the fix.

     5 --- perl-5.12.5/util.c	2014-05-28 12:10:02.250325812 +0200

     6 +++ perl-5.12.5/util.c	2014-05-28 12:09:34.437338588 +0200

     7 @@ -1712,7 +1712,7 @@ Perl_my_setenv(pTHX_ const char *nam, co

     8         my_setenv_format(environ[i], nam, nlen, val, vlen);

     9      } else {

    10  # endif

    11 -#   if defined(__CYGWIN__) || defined(EPOC) || defined(__SYMBIAN32__) || defined(__riscos__)

    12 +#   if defined(__CYGWIN__) || defined(EPOC) || defined(__SYMBIAN32__) || defined(__riscos__) || defined(__sun)

    13  #       if defined(HAS_UNSETENV)

    14          if (val == NULL) {

    15              (void)unsetenv(nam);