After downloading and decompressing the latest 3.6.2 source release, I attempted to build as follows:

    $ ./configure --enable-optimizations --enable-ipv6  # seems fine
    $ make -s -j$(nproc)

At the end of the build I have this error reported:

    Failed to build these modules:
    _socket
    
    
    Following modules built successfully but were removed because they could not be imported:
    _asyncio              _ssl

Scrolling up, I see that the _asyncio and _ssl failures are due to _socket being missing. Scrolling up further, I see several warnings and errors, to wit:

    *a series of tests that seem to go okay*
    0:05:14 load avg: 0.62 [161/405] test_hash
    0:05:15 load avg: 0.65 [162/405] test_hashlib
    Fatal Python error: Segmentation fault
    
    Current thread 0x00002afbece8e380 (most recent call first):
      File "/usr/local/src/python/Python-3.6.2/Lib/test/support/__init__.py", line 1508 in gc_collect
      File "/usr/local/src/python/Python-3.6.2/Lib/test/libregrtest/save_env.py", line 271 in __exit__
      File "/usr/local/src/python/Python-3.6.2/Lib/test/libregrtest/runtest.py", line 172 in runtest_inner
      File "/usr/local/src/python/Python-3.6.2/Lib/test/libregrtest/runtest.py", line 137 in runtest
      File "/usr/local/src/python/Python-3.6.2/Lib/test/libregrtest/main.py", line 374 in run_tests_sequential
      File "/usr/local/src/python/Python-3.6.2/Lib/test/libregrtest/main.py", line 454 in run_tests
      File "/usr/local/src/python/Python-3.6.2/Lib/test/libregrtest/main.py", line 530 in _main
      File "/usr/local/src/python/Python-3.6.2/Lib/test/libregrtest/main.py", line 504 in main
      File "/usr/local/src/python/Python-3.6.2/Lib/test/libregrtest/main.py", line 573 in main
      File "/usr/local/src/python/Python-3.6.2/Lib/test/regrtest.py", line 46 in _main
      File "/usr/local/src/python/Python-3.6.2/Lib/test/regrtest.py", line 50 in <module>
      File "/usr/local/src/python/Python-3.6.2/Lib/runpy.py", line 85 in _run_code
      File "/usr/local/src/python/Python-3.6.2/Lib/runpy.py", line 193 in _run_module_as_main
    Segmentation fault (core dumped)
    
After this, the build seems to think all the tests are done and continues with "Rebuilding with profile guided optimizations:". There are a lot of warnings here, mostly about missing execution counts, which I assume comes from 3/4 of the tests not being run. Later on, however, we have this gem:

    /usr/local/src/python/Python-3.6.2/Modules/socketmodule.c:7693:1: internal compiler error: in edge_badness, at ipa-inline.c:895
     }
     ^
    Please submit a full bug report,
    with preprocessed source if appropriate.
    See <file:///usr/share/doc/gcc-4.8/README.Bugs> for instructions.
    Preprocessed source stored into /tmp/ccMFxPIP.out file, please attach this to your bugreport.
    ERROR: Cannot create report: [Errno 17] File exists: '/var/crash/_usr_lib_gcc_x86_64-linux-gnu_4.8_cc1.1000.crash'

I have gcc (Ubuntu 4.8.4-2ubuntu~14.04.3) 4.8.4

I'm new to building Python and even newer to reporting bugs here, so please let me know what additional information I should provide or steps I should take.