Reproduce SIGSEGV (#574)

[vmarkovtsev]

No description provided.

[stsci-bot]

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I noticed the following issues with this pull request:

• The milestone has not been set (this can only be set by a maintainer)
• Changelog entry not present (or pull request number missing) and neither the Affects-dev nor the no-changelog-entry-needed label are set

Would it be possible to fix these? Thanks!

If there are any issues with this message, please report them here.

[vmarkovtsev]

@drdavella For example, https://travis-ci.org/spacetelescope/asdf/jobs/446063632#L2365

[drdavella]

Thanks, I'll try to track this down today. I added pytest-faulthandler to the travis jobs a while ago, which is very useful for tracing these kinds of failures.

[drdavella]

The only test that fails with this change is this one:
https://github.com/spacetelescope/asdf/blob/32abe89ce024ec93b838bdf684a74662a83ee0f0/asdf/tags/core/tests/test_ndarray.py#L62-L88

Specifically, the failure is caused by this line:
https://github.com/spacetelescope/asdf/blob/32abe89ce024ec93b838bdf684a74662a83ee0f0/asdf/tags/core/tests/test_ndarray.py#L82

Presumably this is because it attempts to write to a memory map that has been opened as read-only. I can reproduce this reliably, but I'm still not entirely certain about the root cause at this point.

My proposal to fix this bug is to deprecate the mode= argument to asdf.open, since I don't think it serves any real purpose and only can lead to issues like this one. See #578 for discussion.

[vmarkovtsev]

Reproduced => no longer needed.