I'm running Squid 3.1.4 on Fedora 13, and all is well. I grabbed a copy of Squid 3.1.6 and tried to compile it, but ran into an error. To my novice eye it looks like I somehow botched a file path. The "configure" script ran with no issues. Here are all of the options I used with it (identical to the ones I used with 3.1.4) : $ ./configure --enable-dlmalloc --enable-linux-netfilter --enable-storeio=ufs,aufs --with-aio-threads=16 Here are the last few lines of compiler output, with the error: ... g++ -DHAVE_CONFIG_H -DDEFAULT_CONFIG_FILE=\"/usr/local/squid/etc/squid.conf\" -DDEFAULT_SQUID_DATA_DIR=\"/usr/local/squid/share\" -DDEFAULT_SQUID_CONFIG_DIR=\"/usr/local/squid/etc\" -I.. -I../include -I../src -I../include -I../src -Wall -Wpointer-arith -Wwrite-strings -Wcomments -Werror -D_REENTRANT -g -O2 -MT LoadableModule.o -MD -MP -MF $depbase.Tpo -c -o LoadableModule.o LoadableModule.cc &&\ mv -f $depbase.Tpo $depbase.Po In file included from ../libltdl/ltdl.h:37, from LoadableModule.cc:10: ../libltdl/libltdl/lt_error.h:35:31: error: libltdl/lt_system.h: No such file or directory make[3]: *** [LoadableModule.o] Error 1 make[3]: Leaving directory `/usr/local/src/squid/squid-3.1.6/src' make[2]: *** [all-recursive] Error 1 make[2]: Leaving directory `/usr/local/src/squid/squid-3.1.6/src' make[1]: *** [all] Error 2 make[1]: Leaving directory `/usr/local/src/squid/squid-3.1.6/src' make: *** [all-recursive] Error 1 This is what I find on the machine: [root@XXXXXXXX /]# find / -type d -name 'libltdl' /usr/local/src/squid/squid-3.1.6/libltdl /usr/local/src/squid/squid-3.1.6/libltdl/libltdl /usr/local/src/squid/squid-3.1.4/libltdl It seems that the "lt_error.h" file expects "lt_system.h" to be in the immediate parent directory, but they are both in the same directory. How did I do that?!?! Here is the line in "lt_error.h" : #include <libltdl/lt_system.h> Anyway, I seem to have created a functional kludge by putting a soft link in the "/usr/local/src/squid/squid-3.1.6/libltdl" directory, like this: lrwxrwxrwx 1 root root 21 Aug 2 16:48 lt_system.h -> ./libltdl/lt_system.h Thanks!