I noticed that the OOB check fails with TIMEOUT in 7.8 on my linux box. It produces SEMIWORKING in 7.6, so something is different in the configure script, although the test itself is identical.

The log doesn't say much. Here's from 7.8:

configure:70034: checking how well OOB handling works configure:70366: /home/mast/Pike/no-changes-7.8/build/linux-x86_64/smartlink gcc -o conftest -g -O3 -pipe -ggdb3 -m64 -I/home/mast/Pike/no-changes-7.8/build/linux-x86_64/bundles/include -I/usr/local/include -I/home/mast/Pike/no-changes-7.8/src -I/home/mast/Pike/no-changes-7.8/build/linux-x86_64 -L/home/mast/Pike/no-changes-7.8/build/linux-x86_64/bundles/lib64 -L/home/mast/Pike/no-changes-7.8/build/linux-x86_64/bundles/lib/64 -L/home/mast/Pike/no-changes-7.8/build/linux-x86_64/bundles/lib/. -L/usr/local/lib -L/usr/lib/gcc/x86_64-linux-gnu/4.4 -R/usr/lib/gcc/x86_64-linux-gnu/4.4 conftest.c -ldl -lrt -lnsl -lm -lpthread -lcrypt >&5 conftest.c: In function 'my_socketpair': conftest.c:362: warning: incompatible implicit declaration of built-in function 'memset' conftest.c: In function 'ping': conftest.c:527: warning: incompatible implicit declaration of built-in function 'exit' conftest.c:535: warning: incompatible implicit declaration of built-in function 'exit' conftest.c: In function 'pong': conftest.c:552: warning: incompatible implicit declaration of built-in function 'exit' conftest.c: In function 'pang': conftest.c:570: warning: incompatible implicit declaration of built-in function 'exit' conftest.c: In function 'main': conftest.c:591: warning: incompatible implicit declaration of built-in function 'exit' configure:70366: $? = 0 configure:70366: ./conftest my_socketpair: succeeded configure:70366: $? = 0 configure:70381: result: TIMEOUT

Compared to 7.6:

configure:50000: checking how well OOB handling works configure:50342: /home/mast/Pike/frozen/build/linux-x86_64/smartlink gcc -o conftest -g -O2 -pipe -Wa,--execstack -I/home/mast/Pike/frozen/build/linux-x86_64/bundles/include -I/usr/local/include -I/home/mast/Pike/frozen/src -I/home/mast/Pike/frozen/build/linux-x86_64 -L/home/mast/Pike/frozen/build/linux-x86_64/bundles/lib -z execstack -R/usr/local/lib -L/usr/local/lib -R/usr/X11R6/lib -L/usr/X11R6/lib -R/usr/lib/gcc/x86_64-linux-gnu/4.4 -L/usr/lib/gcc/x86_64-linux-gnu/4.4 conftest.c -ldl -lrt -lnsl -lm -lpthread -lcrypt >&5 conftest.c: In function 'my_socketpair': conftest.c:333: warning: incompatible implicit declaration of built-in function 'memset' conftest.c: In function 'ping': conftest.c:498: warning: incompatible implicit declaration of built-in function 'exit' conftest.c:506: warning: incompatible implicit declaration of built-in function 'exit' conftest.c: In function 'pong': conftest.c:523: warning: incompatible implicit declaration of built-in function 'exit' conftest.c: In function 'pang': conftest.c:541: warning: incompatible implicit declaration of built-in function 'exit' conftest.c: In function 'main': conftest.c:562: warning: incompatible implicit declaration of built-in function 'exit' configure:50345: $? = 0 configure:50351: ./conftest my_socketpair: succeeded configure:50354: $? = 0 configure:50375: result: SEMIWORKING

I've tried changing the compiler flags to match 7.6 (-O2 instead of -O3 etc), but it doesn't change anything. What could the problem be?