[READY] Add some advice for CentOS/RHEL users

[puremourning]

CentOS/RHEL users don't have a new enough compiler to build ycmd, but we can tell them the best way to get one, because we're nice like that.

See also https://github.com/Valloric/YouCompleteMe/wiki/Full-installation-on-CentOS

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This change is 

[codecov-io]

Codecov Report

Merging #775 into master will not change coverage.
The diff coverage is n/a.

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[bstaletic]

Debian stable can lag a little behind Ubuntu LTS. Should we say something about that too? We have recently had ycm-core/YouCompleteMe#2653.

Anyway, this is . Debian can be addressed in another PR.

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Reviewed 1 of 1 files at r1.
Review status: all files reviewed at latest revision, 1 unresolved discussion.

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cpp/CMakeLists.txt, line 184 at r1 (raw file):

  # is too old.
  #
  # We use ldb_release on linux systems to detect the distro/verseion.

Is ldb_release here a typo?

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Comments from Reviewable

[Valloric]

with minor comments.

Thanks for the PR!

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Review status: all files reviewed at latest revision, 3 unresolved discussions.

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cpp/CMakeLists.txt, line 203 at r1 (raw file):

      message( STATUS "NOTE: You appear to be on ${LSB_RELEASE_ID} version "
      "${LSB_RELEASE_VERSION}. In order to use this application, you require a "
      "more modern compiler than the default. Please install the devtoolset-6 "

I'd clarify this a bit with "the default installed."

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cpp/CMakeLists.txt, line 211 at r1 (raw file):

        message( STATUS "NOTE: It looks like you have the devtoolset-6 "
                        "installed in /opt/rh/devtoolset-6, so you probably "
                        "just need to activate it and re-run the installation" )

This should print the command to activate it.

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Comments from Reviewable

[puremourning]

Debian stable can lag a little behind Ubuntu LTS. Should we say something about that too?

Maybe, but I don't use Debian, so I have no motivation to do so :) The reason for this is really RHEL users in corporate environments (like me: ))

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Review status: 0 of 1 files reviewed at latest revision, 3 unresolved discussions.

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cpp/CMakeLists.txt, line 184 at r1 (raw file):

Previously, bstaletic (Boris Staletic) wrote…

Is ldb_release here a typo?

Yse.

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cpp/CMakeLists.txt, line 203 at r1 (raw file):

Previously, Valloric (Val Markovic) wrote…

I'd clarify this a bit with "the default installed."

Done.

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cpp/CMakeLists.txt, line 211 at r1 (raw file):

Previously, Valloric (Val Markovic) wrote…

This should print the command to activate it.

There are actually a few ways to enable it that work differently dependent on your environment and your shell (which is why I was lazy and didn't include that instruction). I added a simple bash example, which should work for most folk.

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Comments from Reviewable

[micbou]

@zzbot r+

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Reviewed 1 of 1 files at r1, 1 of 1 files at r2.
Review status: all files reviewed at latest revision, 2 unresolved discussions.

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Comments from Reviewable

[zzbot]

📌 Commit 3b3f303 has been approved by micbou

[zzbot]

⌛ Testing commit 3b3f303 with merge 552520f...

[zzbot]

💔 Test failed - status-travis

[micbou]

@zzbot retry

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Review status: all files reviewed at latest revision, 2 unresolved discussions, some commit checks failed.

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Comments from Reviewable

[zzbot]

⌛ Testing commit 3b3f303 with merge 8b5bce1...

[zzbot]

☀️ Test successful - status-travis
Approved by: micbou
Pushing 8b5bce1 to master...