Removing 'build-toolchain' label, which only applies to Chrome OS.

Do you intend to compile for iOS on a Linux? That's not likely to work.

> Do you intend to compile for iOS on a Linux? That's not likely to work.

Sorry the "on Linux" was a mistake (I was reporting several issues in a row). I'm obviously building on a Mac (10.14.2 Mojave)

Hi svillar@, it looks like that error is for downloading clang, which isn't unique to the iOS build.  Are you able to run `gclient sync` for the regular mac checkout?  Can you access `https://commondatastorage.googleapis.com/chromium-browser-clang/Mac/clang-346388-5.tgz` normally?

No I cannot. It failed due to some error in the certificates negotiation.

bash-3.2$ gclient sync
Syncing projects: 100% (106/106), done.                                                        
Running hooks:  17% (13/73) mac_toolchain 
________ running '/Library/Frameworks/Python.framework/Versions/2.7/Resources/Python.app/Contents/MacOS/Python src/build/mac_toolchain.py' in '/Volumes/external/msanchez/work/chromium'
Skipping Mac toolchain installation for mac
Running hooks:  20% (15/73) clang        
________ running '/Library/Frameworks/Python.framework/Versions/2.7/Resources/Python.app/Contents/MacOS/Python src/tools/clang/scripts/update.py --with-android=False' in '/Volumes/external/chromium'
Downloading https://commondatastorage.googleapis.com/chromium-browser-clang/Mac/clang-346388-5.tgz 
<urlopen error [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:726)>
Retrying in 5 s ...
Downloading https://commondatastorage.googleapis.com/chromium-browser-clang/Mac/clang-346388-5.tgz 
<urlopen error [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:726)>
Retrying in 10 s ...

Probably related to the recent change from "Google" to "Google LLC" ?

Is this still an issue? I'd imagine this is transient. 

This is still an issue apparently, I've just git rebased by local checkout, and hit this:

    $ gclient sync
    Syncing projects: 100% (106/106), done.                                                        
    Running hooks:  17% (13/76) mac_toolchain 
    ________ running '/Library/Frameworks/Python.framework/Versions/2.7/Resources/Python.app/Contents/MacOS/Python src/build/mac_toolchain.py' in '/Volumes/external/msanchez/work/chromium'
    Skipping Mac toolchain installation for mac
    Running hooks:  19% (15/76) clang        
    ________ running '/Library/Frameworks/Python.framework/Versions/2.7/Resources/Python.app/Contents/MacOS/Python src/tools/clang/scripts/update.py --with-android=False' in '/Volumes/external/msanchez/work/chromium'
    Downloading https://commondatastorage.googleapis.com/chromium-browser-clang/Mac/clang-346388-5.tgz 
    <urlopen error [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:726)>
    Retrying in 5 s ...


Note that depot_tools is also up-to-date, which I checked in case this could be related to a similar issue that just started happening a few hours ago with git cl upload, see crbug.com/914564. In that case the problem is another SSL: CERTIFICATE_VERIFY_FAILED error, even though in that case the problem seems to be related to depot_tools "downgrading" from httplib version 0.11.3 to version 0.9.2 (so I'm not sure it's the same root cause, since we certainly haven't downgraded python libs in this Mac machine).

This issue seems to be related to outdated certificated installed with the python OS X software distribution. Those can be updated by running `/Applications/Python\ 2.7/Install\ Certificates.command`. This information was taken from https://github.com/tensorflow/tensorflow/issues/10779#issuecomment-309134512.