This might be related to https://crbug.com/893686, recent migration of perf-builder to LUCI broke archiving builds, this got fixed now, but unfortunately builds are missing for this period.

Also I noticed that there was some changes to folder names in GS, I uploaded a new version bisect_builds.py. Please download it from here https://sites.google.com/a/google.com/chrome-te/home/tools/bisect_builds?pli=1 and re-run the bisect.

Thanks prasadv@ for fixing this. This seems to be working fine now with the new version bisect_builds.py on Mac in the range: Good build: 72.0.3588.0 (Revision: 601409)
Bad build : 72.0.3589.0 (Revision: 601810). Earlier, I was facing the error in the same regression range on Mac.  

We will test this on other OS as well and update the behavior.

Tested the per-revision bisect on Windows, Mac and Linux using new version of bisect_builds.py with M-71 and M-72. For these two milestones with new version of bisect_builds.py it's working fine and builds are getting invoked.But, with the same new version of bisect_builds.py for M-70 milestone we are facing error on running per-revision bisect.

Example:
Good: 70.0.3503.0
Bad: 70.0.3504.0
Error: RuntimeError: We don't have enough builds to bisect. revlist: []

Good: 70.0.3502.0
Bad: 70.0.3503.0
Error: RuntimeError: We don't have enough builds to bisect. revlist: []

Good: 70.0.3537.0
Bad: 70.0.3538.0
Error: [Errno 2] No such file or directory

prasadv@ Could you please confirm that we need to raise a separate issue for the same and also is there any issue in running the earlier ranges with the new version of bisect_builds.py

Thanks!

Thanks for the fix in comment 2!  I was hitting this on Windows and doing a "git pull" in my bisect_builds directory (to pick up the fix) resolved it for me.  (I'm bisecting within M72, so I'm not sure about the M70 issue in comment 4.)

We are facing error (comment# 4) for M70 versions of chrome, works fine in M71 and M72. 

Prasad, would you mind taking a look.

The following revision refers to this bug:
  https://chrome-internal.googlesource.com/chrome/test/python_tests/+/624e1bbf134983c382f617b00d051f64cb53a49a

commit 624e1bbf134983c382f617b00d051f64cb53a49a
Author: Prasad Vuppalapu <prasadv@google.com>
Date: Tue Nov 13 22:58:27 2018

Please checkout the latest version of bisect_build.py to verify this.

Issue 916325 has been merged into this issue.