fix(backend): Almost empty error when wsl.exe fails. #120
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If wsl.exe doesn't exit 0, then we read the byte buffer to find "Wsl/Service/WSL_E_DISTRO_NOT_FOUND". By doing so we're exhausting the reader, so the last line of this function essentially assembles an empty message, because there is nothing more to retrieve from the reader. The fix is write the buffer contents into strings and use those when comparing and generating error messages.
didrocks
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Sep 6, 2024
CarlosNihelton
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Dec 10, 2024
``` time=2024-07-24T12:17:10-07:00 level=error msg=Landscape: skipping distro "Ubuntu-24.04" from landscape info: could not get distro "Ubuntu-24.04"'s state: could not get states of distros: exit status 1. Stdout: . Stderr: ``` That happens during construction of the status message sent to Landscape. If we skip a distro, Landscape understands it doesn't exist anymore and removes it from the dashboard. But that happens sometimes when an existing distro. It seems a WSL internal error. ubuntu/GoWSL#120 should prevent the stdout and stderr messages to come empty as shown above. Thus I'm updating GoWSL here. That doesn't prevent the issue itself. I couldn’t reproduce this outside of UP4W. I attempted building a small binary in Go doing the same steps as GoWSL does and put it to run during system startup in loop, rebooted the OS many times but no success. The few times I’ve seen this happening in the logs were early during app startup, so I suspect it may happen because some WSL internal component is not yet ready. Thus this PR: adding one-time retry if an error happens when attempting to retrieve a distro state. Either that will prevent the issue once for all or at least give us more context about what causes that error. --- UDENG-3722
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If wsl.exe doesn't exit 0, then we read the byte buffer to find "Wsl/Service/WSL_E_DISTRO_NOT_FOUND".
By doing so we're exhausting the reader, so the last line of this function essentially assembles an empty message, because there is nothing more to retrieve from the reader.
The fix is write the buffer contents into strings and use those when comparing and generating error messages.
That could be a problem for very long outputs, but wsl.exe itself always generates short messages (currently at least).