Comment 1 for bug 1965165

Trying without --log-regex we have:

 $ ./retry-autopkgtest-regressions --blocks zlib | wc -l
27

 $ ./retry-autopkgtest-regressions --blocks zlib --only-unknown | wc -l
13

[ 10:50AM 10523 ] [ bdmurray@impulse:~/source-trees/ubuntu-archive-tools/ubuntu-archive-tools(main✗) ]
 $ ./retry-autopkgtest-regressions --blocks zlib --log-regex "amss.bin" | wc -l
13
[ 10:51AM 10524 ] [ bdmurray@impulse:~/source-trees/ubuntu-archive-tools/ubuntu-archive-tools(main✗) ]
 $ ./retry-autopkgtest-regressions --blocks zlib --only-unknown --log-regex "amss.bin" | wc -l
13

The list of packages blocking zlib seems to have changed on me but I still think there is something weird going on here.