+ - pkg-config
+
+ Guile's ./configure script uses pkg-config to discover the correct
+ compile and link options for libgc. If you don't have pkg-config
+ installed, or you have a version of libgc that doesn't provide a
+ .pc file, you can work around this by setting some environment
+ variables before running ./configure:
+
+ - PKG_CONFIG=true
+
+ - BDW_GC_CFLAGS=<compile flags for picking up libgc headers>
+
+ - BDW_GC_LIBS=<linker flags for picking up the libgc library>
+