"core dumped" when running Python tests

My builds are failing with a really weird error:

*** Error in `/home/travis/miniconda/envs/test-environment/bin/python': corrupted size vs. prev_size: 0x0000562987d4f800 ***
Fatal Python error: Aborted
Current thread 0x00007f348b5ac740 (most recent call first):
/home/travis/.travis/functions: line 109:  5989 Aborted                 (core dumped) pytest --cov=./ ModelTrainer/ -s
The command "pytest --cov=./ ModelTrainer/ -s" exited with 134.

The tests seem to work, but maybe the build environment broke recently? Could this be a miniconda issue?

See https://travis-ci.org/github/apacha/MusicSymbolClassifier/builds/703135023 for the complete build log.

“core dumped” means a C-level error. Most probably, you have extension modules incompatible with your system, instance of Python and/or each other.

I see that you are using dist: trusty which is EOL, Python from Anaconda (so you can use language: generic because you don’t need Travis’ Python installation logic, it only wastes time and complicates things for you) and installing modules from both Anaconda and PyPI.
Since no-one guarantees PyPI modules’ compatibility with Anaconda Python and Anaconda might have dropped Trusty support (as for individual modules, this is pretty much guaranteed), I’m not very surprised.

You have few chances to find the specific cause:

so the best course of action is to use a supported environment (omit dist:; also pay attention to other warnings at the “View config” tab), then localize the problem: compare module versions to your last successful build and change them one by one (or half at a time to get to a result in a logarithmic number of steps) until you find out which change triggers the problem.