So trying to build pike 8.0 from git, and got an error about Msql:
=== configuring in Msql (/home/riffraff/src/pike/8.0/pike/build/linux-4.16.6-302.fc28.x86_64-x86_64/modules/Msql) configure: running /bin/bash -norc /home/riffraff/src/pike/8.0/pike/src/modules/Msql/configure --disable-option-checking '--prefix=/usr/local' --cache-file=/dev/null --srcdir=/home/riffraff/src/pike/8.0/pike/src/modules/Msql configure: error: cannot find sources (msqlmod.cmod) in /home/riffraff/src/pike/8.0/pike/src/modules/Msql configure: error: /home/riffraff/src/pike/8.0/pike/src/modules/Msql/configure failed for Msql configure: error: /home/riffraff/src/pike/8.0/pike/src/modules/configure failed for modules
ll Msql/ total 52 -rw-rw-r--. 1 riffraff riffraff 403 May 10 20:22 acconfig.h -rw-rw-r--. 1 riffraff riffraff 2948 May 10 20:22 configure.in -rw-rw-r--. 1 riffraff riffraff 187 May 10 20:22 Makefile.in -rw-rw-r--. 1 riffraff riffraff 29556 May 10 20:22 msqlmod.c -rwxrwxr-x. 1 riffraff riffraff 824 May 10 20:22 test_msqlmod.pike -rw-rw-r--. 1 riffraff riffraff 0 May 10 20:22 testsuite.in -rw-rw-r--. 1 riffraff riffraff 334 May 10 20:22 version.h
Looks like you have a configure that was generated of the Pike 8.1 branch. Try rerunning run_autoconfig.
/grubba