The angle_end2end_tests have been failing on the Linux Ozone (Intel) bot for ~3 days:
https://ci.chromium.org/buildbot/chromium.gpu.fyi/Linux%20Ozone%20%28Intel%29/?limit=200

Last good build:
https://ci.chromium.org/buildbot/chromium.gpu.fyi/Linux%20Ozone%20%28Intel%29/4436

First failing build:
https://ci.chromium.org/buildbot/chromium.gpu.fyi/Linux%20Ozone%20%28Intel%29/4437

It looks like the harness is aborting early for some reason. Apparently the only configuration that's supposed to run is ES2_OPENGL. Here's the start of the log from the last good run:

----------
Additional test environment:
  CHROME_DEVEL_SANDBOX=/opt/chromium/chrome_sandbox
  LD_LIBRARY_PATH=/b/c/b/Linux_Ozone__Intel_/src/out/Debug:/b/c/b/Linux_Ozone__Intel_/src/out/Debug/lib:/b/c/b/Linux_Ozone__Intel_/src/out/Debug/lib.target
/b/c/b/Linux_Ozone__Intel_/src/out/Debug/angle_end2end_tests --test-launcher-bot-mode --use-gpu-in-tests --test-launcher-retry-limit=0 --test-launcher-summary-output=/tmp/tmpsbydfu.json
Skipping tests using configuration ES3_OPENGL because it is not available.
Skipping tests using configuration ES3_OPENGLES because it is not available.
Skipping tests using configuration ES3_1_OPENGL because it is not available.
Skipping tests using configuration ES3_1_OPENGLES because it is not available.
Skipping tests using configuration ES2_OPENGL because it is not available.
Skipping tests using configuration ES2_OPENGL_3_3 because it is not available.
Skipping tests using configuration ES3_OPENGL_3_3 because it is not available.
Skipping tests using configuration ES3_OPENGL_4_0 because it is not available.
Skipping tests using configuration ES3_OPENGL_4_1 because it is not available.
Skipping tests using configuration ES3_OPENGL_4_2 because it is not available.
...
-----------

But here's the output from the first failing run:

----------
Additional test environment:
  CHROME_DEVEL_SANDBOX=/opt/chromium/chrome_sandbox
  LD_LIBRARY_PATH=/b/c/b/Linux_Ozone__Intel_/src/out/Debug:/b/c/b/Linux_Ozone__Intel_/src/out/Debug/lib:/b/c/b/Linux_Ozone__Intel_/src/out/Debug/lib.target
/b/c/b/Linux_Ozone__Intel_/src/out/Debug/angle_end2end_tests --test-launcher-bot-mode --use-gpu-in-tests --test-launcher-retry-limit=0 --test-launcher-summary-output=/tmp/tmpYoyCQG.json
Skipping tests using configuration ES3_OPENGL because it is not available.
 killed dbus-daemon with PID 29509
 cleared DBUS_SESSION_BUS_ADDRESS environment variable
step returned non-zero exit code: 252
----------

There's no ANGLE blamelist and nothing in the Chromium blamelist that looks suspicious.

It's not clear to me that this was a silent machine configuration change, though we can ask the Labs team if it looks like it was. Frank, could you please take a first look at this?