Please describe the problem:
This is not a distro specific issue.
Banshee will accept and use --libdir passed to configure for
installing its libs, yet it hardcodes the path in the pkg-config file.
This is inconsistent and needs fixed. Etiher the pkg-config file also
follows --libdir or the install path is hardcoded everywhere. Its the
inconsistency that causes the problem.
My distro (mandriva, though fedora etc also do the same) just chooses
to use set --libdir to /usr/lib64 on 64 bit systems.

As a result its preventing me building banshee-mirage on my x84_64
system;

Making all in Mirage
make[1]: Entering directory `/home/nicbrown/rpm/BUILD/mirage-0.3.0/
Mirage'
gmcs -noconfig -debug -codepage:utf8 -unsafe -warn:4 -d:DEBUG -
out:Mirage.dll -target:library  -r:/usr/lib/banshee-1/
Banshee.Widgets.dll -r:/usr/lib/banshee-1/Banshee.ThickClient.dll -r:/
usr/lib/banshee-1/Banshee.Services.dll -r:Mono.Cairo -r:/usr/lib/
banshee-1/Hyena.Gui.dll -r:/usr/lib/banshee-1/Banshee.Core.dll -
r:System -r:/usr/lib/banshee-1/Mono.Media.dll -r:/usr/lib64/
pkgconfig/../../lib/mono/gtk-sharp-2.0/glib-sharp.dll -r:System.Data -
r:Mono.Data.SqliteClient -r:Mono.Posix -r:/usr/lib/banshee-1/Hyena.dll
-r:/usr/lib/banshee-1/MusicBrainz.dll -r:/usr/lib64/pkgconfig/../../
lib/mono/gtk-sharp-2.0/pango-sharp.dll -r:/usr/lib64/pkgconfig/../../
lib/mono/gtk-sharp-2.0/atk-sharp.dll -r:/usr/lib64/pkgconfig/../../lib/
mono/gtk-sharp-2.0/gdk-sharp.dll -r:/usr/lib64/pkgconfig/../../lib/
mono/gtk-sharp-2.0/gtk-sharp.dll -r:/usr/lib/mono/taglib-sharp/taglib-
sharp.dll -r:/usr/lib/mono/ndesk-dbus-1.0/NDesk.DBus.dll -r:/usr/lib/
mono/ndesk-dbus-glib-1.0/NDesk.DBus.GLib.dll -r:/usr/lib/mono/mono-
addins/Mono.Addins.dll    -resource:./res/dct.filter,dct.filter  -
resource:./res/filterweights.filter,filterweights.filter ./
AudioDecoder.cs ./CovarianceMatrix.cs ./Db.cs ./Dbg.cs ./Matrix.cs ./
Mfcc.cs ./Mir.cs ./Scms.cs ./Vector.cs ./AssemblyInfo.cs
error CS0006: cannot find metadata file `/usr/lib/banshee-1/
Banshee.Widgets.dll'
error CS0006: cannot find metadata file `/usr/lib/banshee-1/
Banshee.ThickClient.dll'
error CS0006: cannot find metadata file `/usr/lib/banshee-1/
Banshee.Services.dll'
error CS0006: cannot find metadata file `/usr/lib/banshee-1/
Hyena.Gui.dll'
error CS0006: cannot find metadata file `/usr/lib/banshee-1/
Banshee.Core.dll'
error CS0006: cannot find metadata file `/usr/lib/banshee-1/
Mono.Media.dll'
error CS0006: cannot find metadata file `/usr/lib/banshee-1/Hyena.dll'
error CS0006: cannot find metadata file `/usr/lib/banshee-1/
MusicBrainz.dll'
Compilation failed: 8 error(s), 0 warnings
make[1]: *** [Mirage.dll] Error 1
make[1]: Leaving directory `/home/nicbrown/rpm/BUILD/mirage-0.3.0/
Mirage'
make: *** [all-recursive] Error 1
error: Bad exit status from /home/nicbrown/rpm/tmp/rpm-tmp.29759
(%build)

Steps to reproduce:
pkg-config --variable=bansheedir banshee-1-core
/usr/lib/banshee-1

cat banshee-1-core.pc.in
prefix=@prefix@
exec_prefix=${prefix}
libdir=${exec_prefix}/lib
bansheedir=${libdir}/banshee-1

Name: Banshee Core
Description: Core APIs for the Banshee Media Framework
Version: @VERSION@
Requires: taglib-sharp ndesk-dbus-1.0 ndesk-dbus-glib-1.0 glib-
sharp-2.0 mono-addins banshee-1-hyena banshee-1-musicbrainz
Libs: -r:${bansheedir}/Banshee.Core.dll

Actual results:


Expected results:


Does this happen every time?
Yes

Other information: