Segfault when installing 2.7.5

Question

I'm on a relatively clean Ubuntu 18.10. I'm trying to start using pyenv and I managed to use it to install python 3.7.2.

However, the second thing I tried was installing a 2.7.5 and that just flat out fails, no matter what I try.

$ pyenv install 2.7.5
Downloading Python-2.7.5.tgz...
-> https://www.python.org/ftp/python/2.7.5/Python-2.7.5.tgz
Installing Python-2.7.5...
patching file ./Modules/readline.c
Hunk #1 succeeded at 204 (offset -2 lines).
Hunk #2 succeeded at 747 (offset -2 lines).
Hunk #3 succeeded at 857 (offset -2 lines).
Hunk #4 succeeded at 905 (offset -13 lines).
patching file ./Lib/site.py
patching file ./Lib/ssl.py
Hunk #2 succeeded at 430 (offset -5 lines).
patching file ./Modules/_ssl.c
Hunk #1 succeeded at 65 (offset -2 lines).
Hunk #2 succeeded at 304 (offset -4 lines).
Hunk #3 succeeded at 1729 (offset -83 lines).

BUILD FAILED (Ubuntu 18.10 using python-build 1.2.9-12-g99092d7f)

Inspect or clean up the working tree at /tmp/python-build.20190219134616.5823
Results logged to /tmp/python-build.20190219134616.5823.log

Last 10 log lines:
        Modules/python.o \
        libpython2.7.a -lpthread -ldl  -lutil   -lm  
/usr/bin/ld: libpython2.7.a(posixmodule.o): in function `posix_tmpnam':
/tmp/python-build.20190219134616.5823/Python-2.7.5/./Modules/posixmodule.c:7515: warning: the use of `tmpnam_r' is dangerous, better use `mkstemp'
/usr/bin/ld: libpython2.7.a(posixmodule.o): in function `posix_tempnam':
/tmp/python-build.20190219134616.5823/Python-2.7.5/./Modules/posixmodule.c:7462: warning: the use of `tempnam' is dangerous, better use `mkstemp'
./python -E -S -m sysconfig --generate-posix-vars
Could not find platform dependent libraries <exec_prefix>
Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>]
make: *** [Makefile:464: pybuilddir.txt] Segmentation fault (core dumped)

Out of curiosity, I tried on a clean newly installed VM and got the same error, but on the official Docker image it does work. So there's got to be something about my environment that's wrong.

But what?

Answer 1

Python 2.7.5 will not build properly with gcc-8 Ubuntu 8.2.0-7ubuntu1 compiler, which is the default one for Ubuntu 18.10.

Simplest way to work around this is to install gcc 7.3.0 and symlink to /usr/bin/gcc.

There is good description how to do that in the answer to this question downgrade-gnu-compilers-ubuntu-18-04.