#20315 Pants leaking install logs to stdout while installing a new version Issue created by grihabor Describe the bug When you run any goal, lets say

pants list ::

, and you don't have the declared pants_version installed yet, pants starts downloading the new version and writes the progress to stdout instead of stderr. Pants version 2.18.1 OS Ubuntu 22.04 Additional info Here is a test `test_script.sh`:

#!/bin/bash

testScript() {
    assertEquals "$(pants list ::)" "//:file"
}

oneTimeSetUp() {
	echo '
[GLOBAL]
pants_version = "2.20.0dev1"

backend_packages = []
    ' >pants.toml
	echo 'data' >file.txt
	echo 'file(name="file", source="file.txt")' >BUILD
}

Here is `pants.toml`:

[GLOBAL]
pants_version = "2.18.1"

backend_packages = [
  "pants.backend.shell",
]

Here is `BUILD`:

shunit2_tests(name="tests")

Here is what you get when you run

pants --no-local-cache test test_script.sh

(make sure to switch pants version to a version you don't have installed):

$ pants --no-local-cache test test_script.sh 
23:06:57.25 [ERROR] Completed: Run tests with Shunit2 - //test_script.sh:tests - failed (exit code 1).
testScript
ASSERT:expected:<Found existing installation: setuptools 58.1.0
Uninstalling setuptools-58.1.0:
  Successfully uninstalled setuptools-58.1.0
//:file> but was:<//:file>

Ran 1 test.

FAILED (failures=2)

Bootstrapping Pants 2.19.0rc2
Installing pantsbuild.pants==2.19.0rc2 into a virtual environment at /home/grihabor/.cache/nce/3d6643e46b53e4cc0b2a0d5c768866226ddce3de1f57f80c4a02d8d39800fa8e/bindings/venvs/2.19.0rc2
New virtual environment successfully created at /home/grihabor/.cache/nce/3d6643e46b53e4cc0b2a0d5c768866226ddce3de1f57f80c4a02d8d39800fa8e/bindings/venvs/2.19.0rc2.
23:06:56.99 [INFO] Initializing scheduler...
23:06:57.13 [INFO] Scheduler initialized.
shunit2:ERROR testScript() returned non-zero return code.



✕ //test_script.sh:tests failed in 22.08s.

I've put everything in a repo to easily test https://github.com/grihabor/pants-writes-to-stdout-bug/tree/master (make sure to switch pants version to a version you don't have installed) pantsbuild/pants