[MacPorts] #16010: Port environment not properly cleared due to Tcl env bug causing patch to try perforce

[MacPorts]

#16010: Port environment not properly cleared due to Tcl env bug causing patch to
try perforce
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  Reporter:  gboyce at badbelly.com  |       Owner:  macports-tickets at lists.macosforge.org
      Type:  defect               |      Status:  new                                  
  Priority:  Normal               |   Milestone:  MacPorts base bugs                   
 Component:  base                 |     Version:  1.6.0                                
Resolution:                       |    Keywords:  tcl environment                      
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Changes (by blb at macports.org):

  * keywords:  => tcl environment
  * summary:  db-4.4.20 fails to patch on a system which uses a local
              perforce repository => Port environment not
              properly cleared due to Tcl env bug causing
              patch to try perforce
  * component:  ports => base
  * milestone:  Port Bugs => MacPorts base bugs

Comment:

 This is an interesting edge case of the Tcl env bug (ticket #13930).
 Namely, even though port clears the environment of those P4* variables,
 they are still set to a blank string (the Tcl env bug itself), and
 apparently even when set only to "", patch tries to access perforce.

 I'm able to fix this by using afb's {{{unsetenv}}} function, but that
 requires the {{{package require Pextlib 1.0}}} in {{{macports.tcl}}}
 ({{{proc mportinit}}}) to be moved up prior to handling the environment,
 since {{{unsetenv}}} is in Pextlib.

-- 
Ticket URL: <http://trac.macports.org/ticket/16010#comment:1>
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