[MacPorts] #17633: MacPorts port needs to be built from an /opt/local-installed MacPorts

[MacPorts]

#17633: MacPorts port needs to be built from an /opt/local-installed MacPorts
------------------------------+---------------------------------------------
 Reporter:  blb@…             |       Owner:  macports-tickets@…                   
     Type:  defect            |      Status:  new                                  
 Priority:  Normal            |   Milestone:  MacPorts 1.8.0                       
Component:  base              |     Version:  1.7.0                                
 Keywords:  prefix            |        Port:                                       
------------------------------+---------------------------------------------
 Building the MacPorts port with a MacPorts install not using /opt/local as
 its prefix can cause issues.  Overriding prefix in the MacPorts Portfile
 (either directly or just overriding --prefix in configure.pre_args)
 doesn't work as MacPorts' configure (via MP_PATH_SCAN) will now ignore
 /opt/local, not your true MacPorts prefix.  Hence it can pick up stuff
 installed in your true MacPorts install.

 This is best demonstrated by installing MacPorts to an alternate path (for
 this example, /mp), and installing the tcl and curl ports.  Now, if you
 just run the configure phase on the MacPorts port, you'll see
 {{{
 checking for Tcl configuration... found /usr/lib/tclConfig.sh
 checking for existence of /usr/lib/tclConfig.sh... loading
 checking for Tcl public headers... /usr/include
 checking for tclsh... /mp/bin/tclsh
 checking for Tcl package directory... /mp/lib/tcl8.5
 checking whether tclsh was compiled with threads... yes
 checking for curl-config... /mp/bin/curl-config
 checking for curl_easy_strerror in -lcurl... no
 }}}
 Note that it now picks up the tcl and curl from your initial MacPorts
 install because you've overridden what it thinks of as prefix, and hence
 doesn't ignore the original install's prefix.

 For now, the MacPorts Portfile errors out if you try to use a port from
 anywhere but /opt/local.

-- 
Ticket URL: <http://trac.macports.org/ticket/17633>
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