Correctly handle "master" feature #322

Job	Run time
duplicates	3s
build_system	23s
build (gcc-13.deb, --mini-tests)	5m 38s
build (gcc-13.deb, --std-tests)	5m 56s
build (gcc-13.deb, --test-libcore)	13m 19s
build (gcc-13.deb, --extended-rand-tests)	8m 24s
build (gcc-13.deb, --extended-regex-example-tests)	6m 6s
build (gcc-13.deb, --extended-regex-tests)	11m 17s
build (gcc-13.deb, --test-successful-rustc --nb-parts 2 --current-part 0)	11m 32s
build (gcc-13.deb, --test-successful-rustc --nb-parts 2 --current-part 1)	11m 35s
build (gcc-13.deb, --projects)	18m 6s
build (gcc-13-without-int128.deb, --mini-tests)	5m 34s
build (gcc-13-without-int128.deb, --std-tests)	5m 57s
build (gcc-13-without-int128.deb, --test-libcore)	13m 23s
build (gcc-13-without-int128.deb, --extended-rand-tests)	8m 3s
build (gcc-13-without-int128.deb, --extended-regex-example-tests)	6m 6s
build (gcc-13-without-int128.deb, --extended-regex-tests)	11m 26s
build (gcc-13-without-int128.deb, --test-successful-rustc --nb-parts 2 --current-part 0)	11m 12s
build (gcc-13-without-int128.deb, --test-successful-rustc --nb-parts 2 --current-part 1)	11m 28s
build (gcc-13-without-int128.deb, --projects)	18m 22s
	3h 3m 50s

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