How do I stop BitBake progress logging?

One might expect that the -s (--silent) option to bitbake would get rid of all the progress reports. But I still get thousands of these lines:

[36A[JRunning tasks (657 of 2070)  31% ||
[36A[JRunning tasks (657 of 2070)  31% ||
[36A[JRunning tasks (657 of 2070)  31% ||
[36A[JRunning tasks (657 of 2070)  31% ||
[36A[JRunning tasks (657 of 2070)  31% ||
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[36A[JRunning tasks (657 of 2070)  31% ||
[36A[JRunning tasks (657 of 2070)  31% ||
[36A[JRunning tasks (657 of 2070)  31% ||
[36A[JRunning tasks (657 of 2070)  31% ||
[36A[JRunning tasks (657 of 2070)  31% ||
[36A[JRunning tasks (657 of 2070)  31% ||
[36A[JRunning tasks (657 of 2070)  31% ||
[36A[JRunning tasks (657 of 2070)  31% ||
[36A[JRunning tasks (657 of 2070)  31% ||
[36A[JRunning tasks (657 of 2070)  31% ||
[36A[JRunning tasks (657 of 2070)  31% ||
[36A[JRunning tasks (657 of 2070)  31% ||
[36A[JRunning tasks (657 of 2070)  31% ||
[36A[JRunning tasks (657 of 2070)  31% ||
[36A[JRunning tasks (657 of 2070)  31% ||
[36A[JRunning tasks (657 of 2070)  31% ||
[36A[JRunning tasks (657 of 2070)  31% ||
[36A[JRunning tasks (657 of 2070)  31% ||
[36A[JRunning tasks (657 of 2070)  31% ||
[36A[JRunning tasks (657 of 2070)  31% ||
[36A[JRunning tasks (657 of 2070)  31% ||
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[36A[JRunning tasks (657 of 2070)  31% ||
[36A[JRunning tasks (657 of 2070)  31% ||
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[36A[JRunning tasks (657 of 2070)  31% ||
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[36A[JRunning tasks (657 of 2070)  31% ||
[36A[JRunning tasks (657 of 2070)  31% ||
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[36A[JRunning tasks (657 of 2070)  31% ||
[36A[JRunning tasks (657 of 2070)  31% ||
[36A[JRunning tasks (657 of 2070)  31% ||
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[36A[JRunning tasks (657 of 2070)  31% ||
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[36A[JRunning tasks (658 of 2070)  31% ||
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[36A[JRunning tasks (658 of 2070)  31% ||
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[36A[JRunning tasks (658 of 2070)  31% ||
[36A[JRunning tasks (658 of 2070)  31% ||
[36A[JRunning tasks (658 of 2070)  31% ||

$TERM is dumb, so there really shouldn't be all those ^[ sequences in there, either. I don't want this crap filling up my build logs; what am I doing wrong?

Solution

The problem is that I was running in a Docker container, and $TERM wasn't explicitly passed. Then Bitbake was making incorrect guess.

The fix was easy: pass -e TERM=${TERM:-dumb} in the docker run command.