dpkg-buildpackage: Do not set PKG_CONFIG_LIBDIR when cross-building

The proper solution to this is to let the build system choose the
appropriate pkg-config binary for the build or host system in the
same way pkg.m4 is handling it now.

Closes: #551118

debian/changelog

@@ -120,6 +120,10 @@ dpkg (1.15.6) UNRELEASED; urgency=low
     Thanks to Jonathan Nieder for the initial patch.
   * Use xz command to handle lzma compressed files in dpkg and dpkg-dev.
     This removes the lzma package from both dpkg and dpkg-dev dependencies.
+  * Do not set PKG_CONFIG_LIBDIR in dpkg-buildpackage when cross-building.
+    The proper solution to this is to let the build system choose the
+    appropriate pkg-config binary for the build or host system in the same
+    way pkg.m4 is handling it now. Closes: #551118
 
   [ Modestas Vainius ]
   * Implement symbol patterns (Closes: #563752). From now on, it is possible to

scripts/dpkg-buildpackage.pl

@@ -29,7 +29,6 @@ use Dpkg::BuildOptions;
 use Dpkg::Compression;
 use Dpkg::Version;
 use Dpkg::Changelog::Parse;
-use Dpkg::Arch qw(get_build_arch debarch_to_gnutriplet);
 
 textdomain("dpkg-dev");
 
@@ -322,16 +321,6 @@ while ($_ = <$arch_env>) {
 }
 close $arch_env or subprocerr('dpkg-architecture');
 
-# In case of cross-compilation, give sensible default search path
-# for some widely used tools
-$targetgnusystem = debarch_to_gnutriplet($targetarch) if $targetarch;
-if ($targetgnusystem and
-    ($targetgnusystem ne debarch_to_gnutriplet(get_build_arch())))
-{
-   $ENV{PKG_CONFIG_LIBDIR} ||= "/usr/$targetgnusystem/lib/pkgconfig/:" .
-                               "/usr/share/pkgconfig/";
-}
-
 my $arch;
 unless ($sourceonly) {
     $arch = mustsetvar($ENV{'DEB_HOST_ARCH'}, _g('host architecture'));