Crater log of "current run" always begins with "previous run"

[RalfJung]

See for instance this report: it seems that the log of a "current run", such as this, is actually the concatenation of the log for the previous run and the current run. That's quite confusing, and it's also new -- in the past, "current run" was just the current run.

[RalfJung]

This seems to happen consistently currently. See for instance https://crater-reports.s3.amazonaws.com/pr-129199/index.html, in "buold (compiler-error)", the only regression. "Current run" links to this which starts with

[INFO] fetching crate vergen-pretty 0.3.4...
[INFO] checking vergen-pretty-0.3.4 against master#426a60abc213b28a7c7198e475476b6e650d871f for pr-129199
[INFO] extracting crate vergen-pretty 0.3.4 into /workspace/builds/worker-7-tc1/source

and then later

[INFO] checking vergen-pretty-0.3.4 against try#2c70eb47850052381670935f807d41647a7dc992 for pr-129199
[INFO] extracting crate vergen-pretty 0.3.4 into /workspace/builds/worker-7-tc2/source

So there are two builds in one logfile, it seems.