Waf does not honour pkg-config settings when cross-compiling

[Paweł Forysiuk]

When cross compiling prefixed pkg-config program should be used for example i686-w64-mingw32-pkg-config when compiling for 32 bits. Waf does not honour this setting by implicitly using native version of pkg-config

114: wscript
    conf.check_tool ('vala')

in .waf-1.5.19-d046dea57dbefcabd071866ac51eb518/wafadmin/Tools/vala.py
call pkg-config implicitly when checking for gobject and gthread
thus prepending native paths to includes, which in turn breaks the build.

Current workaround is to user PKG_CONFIG_LIBDIR env variable which is honoured with internal check vala tool.

Proper way is to use prefixed pkg-config everywhere.

[Paweł Forysiuk (tuxator)]

Attached patch is WIP (assumes cross compilation) and does not fix the issue with internal checks

[Cris Dywan (kalikiana)]

This is essentially obsolete - we'll do whatever's needed with cmake now.