Build does not respect CONFIG_SITE

[wrp (William Pursell)]

In the world of the autotools, it is common to use a CONFIG_SITE to specify parameters to the configure script. There is something about the current macports build that does not play well with this. If the environment variable CONFIG_SITE is set to a path containing the text "prefix=/p/a/t/h", then the build (checked out at [ddc57c5f6ced9ccc0bb4e04e22e218ae851c241d/macports-base]) fails. To be specific:

export CONFIG_SITE=/some/path
echo 'prefix=/p/a/t/h' > $CONFIG_SITE
./configure
make

fails with an error like:

chmod: ${PWD}/vendor/vendor-destroot/p/a/t/h/libexec/macports/lib/tcllib*: No such file or directory

The build works fine if the config site is not used but instead the user invokes the configure script with the prefix specified as an argument.