rename() on directory fails when setting up chromium build environment

[therealkenc]

Setting up the chromium build environment on 15042 fails in a python script with OSError: permission denied. It builds okay on native (natch), and also built okay on earlier WSL, even since before Anniversary Update. I can't definitively point at a WSL regression (i.e. introduced misbehavior), because there are too many moving parts. The last time I looked was back in November, and enough has changed in Ubuntu userspace since then that the change could be python, libraries, or who knows. I don't think it is a change in the chromium package proper, because I tried rolling back to the same version I was using back then and get the same error.

I'm not lovin' the repro here either. Distilled from Google's instructions:

mkdir somewhere && cd somewhere
git clone https://chromium.googlesource.com/chromium/tools/depot_tools.git
export PATH="$PATH:$PWD/depot_tools"
mkdir chromium && cd chromium
fetch --nohooks chromium     # find something else to do for a while
cd src
build/install-build-deps.sh  # step probably not strictly necessary to repro
mkdir strace
strace -ff -o strace/gclient gclient runhooks
grep EACCES strace/*

The error in gclient runhooks is:

lstat("/home/ken/Devel/chromium/src/native_client/toolchain/linux_x86/nacl_arm_glibc/arm-nacl/libexec", 0x7fffe1799960) = -1 ENOENT (No such file or directory)
stat("/home/ken/Devel/chromium/src/native_client/toolchain/linux_x86/nacl_arm_glibc/arm-nacl/libexec", 0x7fffe1799970) = -1 ENOENT (No such file or directory)
rename("/home/ken/Devel/chromium/src/native_client/toolchain/linux_x86/nacl_arm_glibc/.tmp/arm-nacl/libexec", "/home/ken/Devel/chromium/src/native_client/toolchain/linux_x86/nacl_arm_glibc/arm-nacl/libexec") = -1 EACCES (Permission denied)

Of some interest is that .../.tmp/arm-nacl/libexec has permission 0700, which is a little unusual. I checked native, and .../libexec is 0700 there too after the successful rename.

Wondering if it is related to #640 (message). I mention it because running gclient runhooks as root doesn't help. [But you do get a cool message from Google saying "Running depot tools as root is sad."]

[benhillis]

Thanks for the repro, @therealkenc. I'll give this a shot today and see if I can figure out what's falling over.

[therealkenc]

Going to close this one out; the issue count suffers enough around here already. GN still has a beef with #1353, but that is unrelated to this issue tracker. The only package that gclient runhooks above was having a problem with (of the many packages it has to deal with) is nacl_arm_glibc, and something appears to have changed on Google's side since February to (likely unintentionally) right the problem. The above repro steps won't fail off master as of this writing, anyway.

I am also going to speculate that the EACCES problem with rename() is an open file handle related thing like #1529, and hauling down hundreds of megabytes of Chrome isn't the right way to observe filesystem problems. So, until next time...