tags 837614 - unreproducible tags 837622 - unreproducible thanks Please don't use the unreproducible tag in this way.
The bug says "FTBFS in testing", not simply "FTBFS", so the only way to reproduce it is by trying it in testing, where it was reported to fail. If a report said that "ls -l" segfaults, we would never tag it as unreproducible after checking that "ls" alone or "ls --color" does not segfault. If the bug is already fixed in sid, fine, let's call it "already fixed in sid". If the package build-depends on another package which is buggy in stretch and already fixed in sid, fine as well, let's consider it fixed and let's close the bug. But please let us use "unreproducible" only for things we don't really know how to reproduce, which is not the case here. Thanks.