compile error: socket_utils_common_posix.cc:297:42: error: 'TCP_USER_TIMEOUT' was not declared in this scope

[ghost]

Description of the problem / feature request:

I'm unable to build Bazel when targeting CentOS 6 (glibc 2.12.). Bazel 0.24.0 revved grpc from 1.13 to 1.18, and the latter expects the TCP_USER_TIMEOUT socket option to be available if the kernel version is >= 2.6.37. However, grpc sources the socket option from netinet/tcp.h, but the option was not imported to that header until glibc 2.17.

Bugs: what's the simplest, easiest way to reproduce this bug? Please provide a minimal example if possible.

• Provision a CentOS 6 / glibc 2.12 dev environment and attempt to build Bazel 0.24.0.

What operating system are you running Bazel on?

CentOS 7 (using a glibc 2.12 compiler sysroot)

What's the output of bazel info release?

$ bazel info release            
Extracting Bazel installation...                          
Starting local Bazel server and connecting to it...       
release 0.23.2+vmware_bootstrap

If bazel info release returns "development version" or "(@Non-Git)", tell us how you built Bazel.

n/a

What's the output of git remote get-url origin ; git rev-parse master ; git rev-parse HEAD ?

n/a

Have you found anything relevant by searching the web?

No, though I haven't looked thoroughly.

Any other information, logs, or outputs that you want to share?

Pull request coming shortly.