In tests, keep reading buffered child process output even after it has exited #2923
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
teor2345
added
C-bug
|
I'm testing this branch locally on macOS as well. |
dconnolly
reviewed
Oct 21, 2021
Comment on lines
+290
to
+292
| // We don't check `is_running` here, | ||
| // because we want to read to the end of the buffered output, | ||
| // even if the child process has exited. |
dconnolly
approved these changes
Oct 21, 2021
|
(This branch passed the |
This was referenced Nov 1, 2021
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Motivation
Some OSes (macOS) have large buffers between child and parent processes.
We need to flush the entire buffer on the child side before exiting (PR #2911).
Then we need to read the entire buffer on the test side, and flush test output to the test runner process. (This PR.)
This is unexpected work in sprint 21.
Specifications
This is a known issue in Rust:
rust-lang/rust#23818 (comment)
Solution
Review
This fix is urgent, because it is causing failures like:
https://github.com/ZcashFoundation/zebra/runs/3954220535#step:10:1356
Anyone can review.
Reviewer Checklist
Follow Up Work
If this PR doesn't fix the issue, we should disable the test, and open a ticket to do a fix later.