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Commit c04f0d41 authored by Tobias Werth's avatar Tobias Werth Committed by Copybara-Service
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Use less subshells and `tee`s in running tests with `bazel run`.

Fixes #17754.

What we have seen prior to this change was that sometimes for quick tests the output was swallowed. After a lot of poking it became clear that the culprit is the use of subshell and `tee`, e.g. if you remove `tee` completely from the picture the behavior never shows up.

The issue is that with a fast test, `tee` seems to be killed (or its parent subshell) before the printing the output to stdout.

With this change, we reduce the number of subshells and processes to set up and reduce the chance of the race condition but not remove it.

However, for practical purposes, the race condition is gone.

With the reproduction steps in #17754, and this command
```
for i in {1..10000}; do /tmp/bazel run :foo &> /tmp/log ; grep -q "useful echo" /tmp/log ; if [ $? -eq 0 ]; then echo -n '+'; else  echo -n '-'; fi; done
```
a bazel from head fails ~3900 out of 10000 times.

After this commit, it never failed.

Closes #17846.

PiperOrigin-RevId: 518794237
Change-Id: I8c1862d3a274799b864f0f5f42b85d6df5af78c7
parent c82168ee
No related merge requests found
......@@ -323,9 +323,9 @@ if [[ "${EXPERIMENTAL_SPLIT_XML_GENERATION}" == "1" ]]; then
fi
else
if [ -z "$COVERAGE_DIR" ]; then
("${TEST_PATH}" "$@" 2> >(tee -a "${XML_OUTPUT_FILE}.log" >&2) 1> >(tee -a "${XML_OUTPUT_FILE}.log") 2>&1) <&0 &
("${TEST_PATH}" "$@" 2>&1 | tee -a "${XML_OUTPUT_FILE}.log") <&0 &
else
("$1" "$TEST_PATH" "${@:3}" 2> >(tee -a "${XML_OUTPUT_FILE}.log" >&2) 1> >(tee -a "${XML_OUTPUT_FILE}.log") 2>&1) <&0 &
("$1" "$TEST_PATH" "${@:3}" 2>&1 | tee -a "${XML_OUTPUT_FILE}.log") <&0 &
fi
fi
childPid=$!
......
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