The following revision refers to this bug:
  https://webrtc.googlesource.com/src.git/+/dc221515ff6876e9fb3cf4f9ac4d308c8945c877

commit dc221515ff6876e9fb3cf4f9ac4d308c8945c877
Author: Oleh Prypin <oprypin@webrtc.org>
Date: Thu Feb 01 19:26:24 2018

Remove win_chromium_webrtc_compile_rel_ng from CQ

It is broken by very long file names in Chromium.

TBR=phoglund@webrtc.org

Bug:  chromium:808111 
Change-Id: If3dd556be506b90f8efaa01c50e3d8608ba9be20
No-Try: True
Reviewed-on: https://webrtc-review.googlesource.com/46104
Reviewed-by: Oleh Prypin <oprypin@webrtc.org>
Commit-Queue: Oleh Prypin <oprypin@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#21854}
[modify] https://crrev.com/dc221515ff6876e9fb3cf4f9ac4d308c8945c877/infra/config/cq.cfg

I'm working on a fix, should be up shortly

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/1aa8a5ebe052ab87e9cce0d181ad92529045b1e2

commit 1aa8a5ebe052ab87e9cce0d181ad92529045b1e2
Author: Stefan Zager <szager@chromium.org>
Date: Thu Feb 01 19:39:42 2018

[RootLayerScrolls] Shorten test names

The long test names were causing failures on Windows, which
evidently has a too-low limit on file name length.

BUG= 808111 
TBR=skobes@chromium.org,oprypin@chromium.org
NOTRY=true

Cq-Include-Trybots: master.tryserver.blink:linux_trusty_blink_rel;master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
Change-Id: I67181501b11963362e8aac0ae1782e2cfe7c1b4a
Reviewed-on: https://chromium-review.googlesource.com/898062
Reviewed-by: Stefan Zager <szager@chromium.org>
Cr-Commit-Position: refs/heads/master@{#533777}
[modify] https://crrev.com/1aa8a5ebe052ab87e9cce0d181ad92529045b1e2/third_party/WebKit/LayoutTests/FlagExpectations/enable-slimming-paint-v2
[rename] https://crrev.com/1aa8a5ebe052ab87e9cce0d181ad92529045b1e2/third_party/WebKit/LayoutTests/compositing/layer-creation/impl-thread-scrolling-non-composited-fixed-no-scroll-expected.txt
[rename] https://crrev.com/1aa8a5ebe052ab87e9cce0d181ad92529045b1e2/third_party/WebKit/LayoutTests/compositing/layer-creation/impl-thread-scrolling-non-composited-fixed-no-scroll.html
[rename] https://crrev.com/1aa8a5ebe052ab87e9cce0d181ad92529045b1e2/third_party/WebKit/LayoutTests/compositing/layer-creation/main-thread-scrolling-non-composited-fixed-overflow-hidden-expected.txt
[rename] https://crrev.com/1aa8a5ebe052ab87e9cce0d181ad92529045b1e2/third_party/WebKit/LayoutTests/compositing/layer-creation/main-thread-scrolling-non-composited-fixed-overflow-hidden.html
[rename] https://crrev.com/1aa8a5ebe052ab87e9cce0d181ad92529045b1e2/third_party/WebKit/LayoutTests/flag-specific/disable-blink-features=RootLayerScrolling/compositing/layer-creation/impl-thread-scrolling-non-composited-fixed-no-scroll-expected.txt
[rename] https://crrev.com/1aa8a5ebe052ab87e9cce0d181ad92529045b1e2/third_party/WebKit/LayoutTests/flag-specific/disable-blink-features=RootLayerScrolling/compositing/layer-creation/main-thread-scrolling-non-composited-fixed-overflow-hidden-expected.txt
[rename] https://crrev.com/1aa8a5ebe052ab87e9cce0d181ad92529045b1e2/third_party/WebKit/LayoutTests/flag-specific/disable-blink-features=RootLayerScrolling/virtual/spv175/compositing/layer-creation/impl-thread-scrolling-non-composited-fixed-no-scroll-expected.txt
[rename] https://crrev.com/1aa8a5ebe052ab87e9cce0d181ad92529045b1e2/third_party/WebKit/LayoutTests/flag-specific/disable-blink-features=RootLayerScrolling/virtual/spv175/compositing/layer-creation/main-thread-scrolling-non-composited-fixed-overflow-hidden-expected.txt
[rename] https://crrev.com/1aa8a5ebe052ab87e9cce0d181ad92529045b1e2/third_party/WebKit/LayoutTests/flag-specific/root-layer-scrolls/compositing/layer-creation/impl-thread-scrolling-non-composited-fixed-no-scroll-expected.txt
[rename] https://crrev.com/1aa8a5ebe052ab87e9cce0d181ad92529045b1e2/third_party/WebKit/LayoutTests/flag-specific/root-layer-scrolls/compositing/layer-creation/main-thread-scrolling-non-composited-fixed-overflow-hidden-expected.txt
[rename] https://crrev.com/1aa8a5ebe052ab87e9cce0d181ad92529045b1e2/third_party/WebKit/LayoutTests/virtual/spv175/compositing/layer-creation/impl-thread-scrolling-non-composited-fixed-no-scroll-expected.txt
[rename] https://crrev.com/1aa8a5ebe052ab87e9cce0d181ad92529045b1e2/third_party/WebKit/LayoutTests/virtual/spv175/compositing/layer-creation/main-thread-scrolling-non-composited-fixed-overflow-hidden-expected.txt

Reassigning to oprypin@ to reenable the webrtc builder.

Thanks for the quick fix!
I'm just watching if the next build will succeed https://build.chromium.org/p/tryserver.webrtc/builders/win_chromium_webrtc_compile_rel_ng/builds/933

But it failed :(

error: unable to create file third_party/WebKit/LayoutTests/flag-specific/disable-blink-features=RootLayerScrolling/platform/linux/virtual/spv175/paint/invalidation/background/viewport-gradient-background-html-move-overflow-expected.txt: Filename too long
error: unable to create file third_party/WebKit/LayoutTests/flag-specific/disable-blink-features=RootLayerScrolling/platform/linux/virtual/spv175/paint/invalidation/background/viewport-gradient-background-html-resize-overflow-expected.txt: Filename too long
error: unable to create file third_party/WebKit/LayoutTests/flag-specific/disable-blink-features=RootLayerScrolling/platform/linux/virtual/threaded/printing/fixed-positioned-headers-and-footers-absolute-covering-some-pages-expected.txt: Filename too long
error: unable to create file third_party/WebKit/LayoutTests/flag-specific/disable-blink-features=RootLayerScrolling/virtual/spv175/paint/invalidation/compositing/dont-invalidate-root-layer-when-composited-layer-becomes-visible-expected.txt: Filename too long
error: unable to create file third_party/WebKit/LayoutTests/flag-specific/disable-blink-features=RootLayerScrolling/virtual/spv175/paint/invalidation/compositing/should-not-repaint-composited-descendants-on-overflow-change-expected.txt: Filename too long


By the way, see the longest file names:

git ls-files | perl -ne '@a = <>; print sort { length $b <=> length $a } @a' | less
# https://stackoverflow.com/a/38899580

Before this change:
./virtual/spv175/compositing/layer-creation/main-thread-scrolling-for-non-composited-fixed-position-if-overflow-hidden-expected.txt
./virtual/spv175/compositing/layer-creation/no-main-thread-scrolling-for-non-composited-fixed-position-without-scroll-expected.txt
./virtual/spv175/paint/invalidation/compositing/dont-invalidate-root-layer-when-composited-layer-becomes-visible-expected.txt
./platform/linux/virtual/spv175/paint/invalidation/background/viewport-gradient-background-html-resize-overflow-expected.txt
./platform/linux/virtual/spv175/paint/invalidation/background/viewport-gradient-background-html-move-overflow-expected.txt
./virtual/spv175/paint/invalidation/compositing/should-not-repaint-composited-descendants-on-overflow-change-expected.txt
./platform/linux/virtual/threaded/printing/fixed-positioned-headers-and-footers-absolute-covering-some-pages-expected.txt
After this change:
./virtual/spv175/paint/invalidation/compositing/dont-invalidate-root-layer-when-composited-layer-becomes-visible-expected.txt
./platform/linux/virtual/spv175/paint/invalidation/background/viewport-gradient-background-html-resize-overflow-expected.txt
./platform/linux/virtual/spv175/paint/invalidation/background/viewport-gradient-background-html-move-overflow-expected.txt
./virtual/spv175/paint/invalidation/compositing/should-not-repaint-composited-descendants-on-overflow-change-expected.txt
./platform/linux/virtual/threaded/printing/fixed-positioned-headers-and-footers-absolute-covering-some-pages-expected.txt
./virtual/spv175/paint/invalidation/table/composited-table-background-section-composited-row-initial-empty-expected.txt
./virtual/spv175/paint/invalidation/window-resize/window-resize-background-image-fixed-centered-composited-expected.txt
./platform/linux/paint/invalidation/table/composited-table-background-section-composited-row-initial-empty-expected.txt

We're not in a rush, by the way

I'm curious what the configuration is for that builder.  We're not having this problem on Windows chromium builders.

Is it possible to get interactive login access to one of the machines, to poke around and figure out why it has this limit of filename length?

It could be just the longer trybot name
C:\b\c\b\win_chromium_webrtc_compile_rel_ng\src
vs
E:\b\c\b\win\src
https://ci.chromium.org/buildbot/tryserver.chromium.win/win_chromium_compile_rel_ng

Either way, this is cutting it too close. Is it really a good idea to make Chromium compilable only if the path has 20 or less characters?

You should be able to get access to the machines (you can find which one on the trybot page) but that's not advisable.
https://chrome-internal.googlesource.com/infra/infra_internal/+/master/doc/ssh.md

I wonder if setting core.longpaths would help.
https://stackoverflow.com/questions/22575662/filename-too-long-in-git-for-windows

Making this available and adding infra>git component.

We have just 5 files remaining that break the limit. Would you consider shrinking them?

len(r'''C:\b\c\builder\win_chromium_webrtc_compile_rel_ng\src/third_party/WebKit/LayoutTests/flag-specific/disable-blink-features=RootLayerScrolling/platform/linux/virtual/threaded/printing/fixed-positioned-headers-and-footers-absolute-covering-some-pages-expected.txt''')
260

longpaths is a hack with caveats

I can fix those 5, but it will be a very fragile fix, as there are numerous files that are *just* under the limit:

$ git ls-files third_party/WebKit/LayoutTests | while read fn; do echo ${#fn}; done | sort -n | uniq -c | tail -20
     15 192
     11 193
     11 194
     11 195
      9 196
     12 197
      8 198
      1 199
      5 200
      5 201
      3 202
      3 203
      3 204
      2 206
      1 207
      1 209
      1 210
      1 215
      1 216

https://bugs.chromium.org/p/webrtc/issues/detail?id=8843 as an example of this being harmful beyond bots.

The bot is still disabled BTW

Issue 813156 has been merged into this issue.

I spent some time trying to understand why

CURRENT_DIR: 'C:\\b\\c\\builder\\win_chromium_webrtc_compile_rel_ng'

is

CURRENT_DIR: 'E:\\b\\c\\b\\win'

for the chromium buildbot. The config for my bot is exactly the same as the chromium bots, so I assume there's a lower level hack somewhere that rewrites the path.

Anyway, I think I can solve this by just shortening the bot names a bit:

len("C:\b\c\builder\win_chromium_webrtc_compile_rel_ng\src\third_party/WebKit/LayoutTests/flag-specific/disable-blink-features=RootLayerScrolling/platform/linux/virtual/spv175/paint/invalidation/background/viewport-gradient-background-html-move-overflow-expected.txt")
258
>>> len("C:\b\c\builder\win_chromium_compile\src\third_party/WebKit/LayoutTests/flag-specific/disable-blink-features=RootLayerScrolling/platform/linux/virtual/spv175/paint/invalidation/background/viewport-gradient-background-html-move-overflow-expected.txt")
244

win_chromium_compile is expressive enough and it cuts 14 chars, which should get us under the limit.

CLs in flight

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/24ce208cd5b6d61b18f47a0664e4e3ca973c496c

commit 24ce208cd5b6d61b18f47a0664e4e3ca973c496c
Author: Patrik Höglund <phoglund@chromium.org>
Date: Wed Feb 21 14:09:32 2018

Shorten WebRTC compile trybot names (chromium).

Example: win_chromium_webrtc_compile_rel_ng -> win_chromium_compile.
These bot names ended up being a bit longer than names usually are, and
this caused us to run into the 260-char limit on paths in Windows.

Bug:  chromium:808111 
Change-Id: Ibc6a09adf5f08ded1bb8d60635ba7fce88203751
Reviewed-on: https://chromium-review.googlesource.com/926010
Commit-Queue: Patrik Höglund <phoglund@chromium.org>
Reviewed-by: John Budorick <jbudorick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#538092}
[modify] https://crrev.com/24ce208cd5b6d61b18f47a0664e4e3ca973c496c/testing/buildbot/tryserver.webrtc.json
[modify] https://crrev.com/24ce208cd5b6d61b18f47a0664e4e3ca973c496c/testing/buildbot/waterfalls.pyl
[modify] https://crrev.com/24ce208cd5b6d61b18f47a0664e4e3ca973c496c/tools/mb/mb_config.pyl

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/tools/build/+/68682249fa8f7b7b3fa7535c293d44bd9d4e89b5

commit 68682249fa8f7b7b3fa7535c293d44bd9d4e89b5
Author: Patrik Höglund <phoglund@chromium.org>
Date: Thu Feb 22 09:12:02 2018

Shorten WebRTC compile trybot names.

Example: win_chromium_webrtc_compile_rel_ng -> win_chromium_compile.
These bot names ended up being a bit longer than names usually are, and
this caused us to run into the 260-char limit on paths in Windows.

Bug:  chromium:808111 
Change-Id: I977c8a3312948bb9bc1be3ec20f4a52f091c0ed1
Reviewed-on: https://chromium-review.googlesource.com/926131
Commit-Queue: Patrik Höglund <phoglund@chromium.org>
Reviewed-by: John Budorick <jbudorick@chromium.org>

[modify] https://crrev.com/68682249fa8f7b7b3fa7535c293d44bd9d4e89b5/masters/master.tryserver.webrtc/slaves.cfg
[modify] https://crrev.com/68682249fa8f7b7b3fa7535c293d44bd9d4e89b5/masters/master.tryserver.webrtc/master.cfg
[modify] https://crrev.com/68682249fa8f7b7b3fa7535c293d44bd9d4e89b5/scripts/slave/recipe_modules/chromium_tests/tryserver_webrtc.py
[modify] https://crrev.com/68682249fa8f7b7b3fa7535c293d44bd9d4e89b5/scripts/slave/recipe_modules/chromium_tests/trybots.py

The following revision refers to this bug:
  https://webrtc.googlesource.com/src.git/+/5283022790de569cd0792fbd9d434f1fb56ce289

commit 5283022790de569cd0792fbd9d434f1fb56ce289
Author: Oleh Prypin <oprypin@webrtc.org>
Date: Thu Feb 22 10:06:20 2018

Shorten Chromium compile trybot names

Bug:  chromium:808111 
Change-Id: I50b1e3155c29a68230c2bebbb260284880e5b953
No-Try: True
TBR: phoglund@webrtc.org
Reviewed-on: https://webrtc-review.googlesource.com/56601
Reviewed-by: Oleh Prypin <oprypin@webrtc.org>
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Commit-Queue: Oleh Prypin <oprypin@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#22145}
[modify] https://crrev.com/5283022790de569cd0792fbd9d434f1fb56ce289/infra/config/cq.cfg

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/d47ccb2b5b2b1e49e3fc07464a776a93d2777816

commit d47ccb2b5b2b1e49e3fc07464a776a93d2777816
Author: Oleh Prypin <oprypin@chromium.org>
Date: Fri Mar 09 08:26:20 2018

Stop building 'all' in WebRTC-in-Chromium tryjobs

Instead build just the targets in chromium.webrtc.

Bonus: remove obsolete tryjob definitions.

Bug:  chromium:820041 ,  chromium:808111 
TBR: machenbach@chromium.org
No-Try: True
Change-Id: I133593a4e51a5e1dac4d0e24d21601cd553784a0
Reviewed-on: https://chromium-review.googlesource.com/956043
Reviewed-by: Patrik Höglund <phoglund@chromium.org>
Commit-Queue: Oleh Prypin <oprypin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#542062}
[modify] https://crrev.com/d47ccb2b5b2b1e49e3fc07464a776a93d2777816/testing/buildbot/tryserver.webrtc.json
[modify] https://crrev.com/d47ccb2b5b2b1e49e3fc07464a776a93d2777816/testing/buildbot/waterfalls.pyl