This was likely harmlessly causing `go get` reruns, since most (all?) real dependency errors cause `go list` to exit with a nonzero return code in any case.
This reverts to the old behavior of reusing the package directory when looking for go.mod. It seems unlikely that this is the right thing to do since we failed to find the module directory, but this behavior should be consistent with what we had before.
The TRAP writer already buffers writes before emitting to file, but running gzip compression is also fairly costly (especially if you only do it a couple of bytes at a time). Thus, this injects another buffer that collects the emitted tuples in string form, and only triggers gzip compression once the buffer is full. In my local testing, this buffering was actually more beneficial than the one between gzip and file (likely because the gzip writer already emits data in chunks), but that one is still beneficial.
As of go 1.19 it will try to format markdown nicely, but in both these cases the formatting isn't supposed to be interpreted this way, so indent it to make it a preformatted block.
