Thank you for your most helpful replies. I did: 1: sudo ldconfig
Output: /sbin/ldconfig.real: /usr/local/lib/libguile-2.0.so.22.7.2-gdb.scm is not an ELF file - it has the wrong magic bytes at the start. 2: pkg-config --cflags --libs guile-2.0 and now things are working (I have only done some very simple things to test). I do not have the foggiest idea why it was so easy. In theory, neither 1 nor 2 should have worked. 1: if gcc really did not know to search in /usr/local/lib I would have expected all manner of previous successful compiles to fail. File /etc/ld.so.conf.d/libc.conf (date April 2012) lists /usr/local/lib . No file in this directory mentions Guile. 2: From the man page I expected to have to insert the output of 2 into a Makefile. (Which Makefile? where? I dont know. ) Also I dont think I sudo-ed 2. I intend to use both make check and make installcheck if I have to re-install because they test different things. I feel confident that the problem I reported in my OP is much more likely a bug in make install than in make installcheck . Thank you
