(Same for Mac) 

https://build.chromium.org/p/chromium.fyi/builders/WebKit%20Linux%20-%20WPTServe
https://build.chromium.org/p/chromium.fyi/builders/WebKit%20Mac%20-%20WPTServe

Example log:
https://luci-logdog.appspot.com/v/?s=chromium%2Fbb%2Fchromium.fyi%2FWebKit_Linux_-_WPTServe%2F7515%2F%2B%2Frecipes%2Fsteps%2Fwebkit_tests%2F0%2Fstdout

14:02:00.278 12330 Command line: /b/c/b/WebKit_Linux___WPTServe/src/out/Release/content_shell --run-layout-test --enable-crash-reporter --crash-dumps-dir=/b/c/b/WebKit_Linux___WPTServe/src/out/Release/crash-dumps -
14:02:00.278 12330 
14:02:00.278 12330 Collecting tests ...
14:02:04.871 12330 Parsing expectations ...
14:02:08.410 12330 Found 74375 tests; running 47388, skipping 26987.
14:02:08.411 12330 Checking build ...
14:02:08.449 12330 
14:02:08.464 12330 "ruby --version" took 0.02s
14:02:08.474 12330 "/usr/bin/wdiff --help" took 0.01s
14:02:08.495 12330 "/usr/sbin/apache2 -v" took 0.02s
14:02:08.495 12330 Checking system dependencies ...
14:02:08.671 12330 "/b/c/b/WebKit_Linux___WPTServe/src/out/Release/content_shell --check-layout-test-sys-deps" took 0.14s
14:02:08.672 12330 Clobbering old results in /b/rr/tmpcQdO6t/w
14:02:08.682 12330 Starting WPTServe ...
14:02:08.683 12330 stale wptserve pid file, pid 13335
14:02:08.683 12330 Checking whether pid 13335 is alive.
14:02:08.683 12330 Checking whether pid 13335 is alive.
14:02:08.683 12330 Checking whether pid 13335 is alive.
...

This step has been running for over 100 hours generating gigabytes of logs, eventually causing https://bugs.chromium.org/p/chromium/issues/detail?id=680142

Until this is fixed, I'll be disabling these builders, since they continue to spam master1 with tons of logs.

---

Dirk, please triage it, I don't know who is supposed to own this test (and what WPT is..). The person who've added these builders is no longer at Google (see https://bugs.chromium.org/p/chromium/issues/detail?id=581386).