Installing gccgo breaks clang++

[Václav Haisman]

The clang++ driver will not find standard C++ headers and the libstdc++ library when there is gccgo-4.9 package installed as well. This appears to be due to gccgo-4.9 installing few things into /usr/bin/lib/gcc/x86_64-linux-gnu/4.9. The clang++ driver sees this directory and thinks it contains full C++ headers and run time installation when it does not, because there are only some parts relevant to gccgo-4.9. Uninstalling gccgo-4.9 fixes the issue because clang++ then finds only the 4.8 directory and uses that.

The same issue occurs with gccgo-5 and GCC 5, which installs a partial GCC 5 installation, enough for the clang++ driver to try to use it but not including libstdc++ so clang++ fails to build.

ProblemType: Bug
DistroRelease: Ubuntu 14.04, Ubuntu 15.04
Package: clang-3.5 1:3.5~svn201651-1ubuntu1
ProcVersionSignature: Ubuntu 3.13.0-24.46-generic 3.13.9
Uname: Linux 3.13.0-24-generic x86_64
ApportVersion: 2.14.1-0ubuntu3
Architecture: amd64
CurrentDesktop: XFCE
Date: Sun Apr 27 18:38:36 2014
InstallationDate: Installed on 2011-11-13 (896 days ago)
InstallationMedia: Xubuntu 11.10 "Oneiric Ocelot" - Release amd64 (20111012)
SourcePackage: llvm-toolchain-snapshot
UpgradeStatus: Upgraded to trusty on 2014-04-19 (8 days ago)

[Václav Haisman (vzeman79)]

Attached bad.txt shows how it looks like when it does not work.

[Václav Haisman (vzeman79)]

The attached file shows how it looks like when it works.

[Matthias Klose (doko)]

there is nothing to do in gccgo, clang shouldn't have such a bad check for whatever

[Robert Knight (robertknight)]

The same issue occurs with gccgo-5 on Ubuntu 15.04, this time installing gccgo-5 causes a partial installation of GCC 5 to be installed. clang++ then tries to use the partial GCC 5 install instead of GCC 4.9 and fails because libstdc++ is missing from the GCC 5 partial installation in /usr/lib/gcc/x86_64-linux-gnu/5.0.1

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.