Autotools pain, configure script fails

All can be seen in the ImprovingMakefile branch of the GitHub - HamAndEggs/seabang: Allows you to run c++ source file as a script repo.

The error I get is
./configure: line 4401: .: filename argument required
.: usage: . filename [arguments]

The line at 4401 is " $ac_cs_success || as_fn_exit 1"
The script is auto generated. So even if I hack it the hack will be lost then next time I regenerate the scripts.

Anyone know how to fix?

P.s. Below is the output when ran.

checking for a BSD-compatible install... /usr/bin/install -c
checking whether build environment is sane... yes
checking for a thread-safe mkdir -p... /usr/bin/mkdir -p
checking for gawk... gawk
checking whether make sets $(MAKE)... yes
checking whether make supports nested variables... yes
checking for g++... g++
checking whether the C++ compiler works... yes
checking for C++ compiler default output file name... a.out
checking for suffix of executables... 
checking whether we are cross compiling... no
checking for suffix of object files... o
checking whether we are using the GNU C++ compiler... yes
checking whether g++ accepts -g... yes
checking whether make supports the include directive... yes (GNU style)
checking dependency style of g++... gcc3
checking that generated files are newer than configure... done
configure: creating ./config.status
config.status: creating Makefile
config.status: executing depfiles commands
./configure: line 4401: .: filename argument required
.: usage: . filename [arguments]

I think it’s time to switch to CMake. I would have preferred to have used autotools as it does not require the user (not the developer) to have any other package expect for their compiler installed. User just does “./configure && make && make install”.

CMake adds a dependency for the user to ensure they have installed, cmake. But the auto tools documentation is obtuse at best and deliberately impenetrable at worse.