Boost C++ Libraries: Ticket #10258: b2 fails to find gcc if bootstrapped with clang

Vladimir Prus — Mon, 28 Jul 2014 10:19:59 GMT

Could you please say how "./b2 toolset=gcc ..." fails exactly? What's your project-config.jam?

Niall Douglas — Mon, 28 Jul 2014 10:26:33 GMT

Could you please say how "./b2 toolset=gcc ..." fails exactly? What's your project-config.jam?

You can see a failing build log at https://ci.nedprod.com/view/Boost.AFIO/job/Boost.AFIO%20Build%20POSIX_ARM_GCC%204.8/10/console.

There is no project-config.jam. Everything is entirely set to default vanilla settings. It could be an ARM Linux thing.

Jürgen Hunold — Tue, 29 Jul 2014 06:38:09 GMT

bootstrap.sh creates a project-config.jam in BOOST_ROOT which contains the default compiler setup. Please take a look for it and tell us the contents. Your error log contains "/bin/sh: 2: -ftemplate-depth-128: not found" which is the classic indication that the (default) compiler is missing/not found/somehow got lost.

Niall Douglas — Tue, 29 Jul 2014 10:20:34 GMT

When bootstrapped with no arguments:

# Boost.Build Configuration
# Automatically generated by bootstrap.sh
import option ;
import feature ;
# Compiler configuration. This definition will be used unless
# you already have defined some toolsets in your user-config.jam
# file.
if ! gcc in [ feature.values <toolset> ]
{
    using gcc ;
}
project : default-build <toolset>gcc ;
# Python configuration
using python : 2.7 : /usr ;
# List of --with-<library> and --without-<library>
# options. If left empty, all libraries will be built.
# Options specified on the command line completely
# override this variable.
libraries =  ;
# These settings are equivivalent to corresponding command-line
# options.
option.set prefix : /usr/local ;
option.set exec-prefix : /usr/local ;
option.set libdir : /usr/local/lib ;
option.set includedir : /usr/local/include ;
# Stop on first error
option.set keep-going : false ;

When bootstrapped with --with-toolset=clang:

# Boost.Build Configuration
# Automatically generated by bootstrap.sh
import option ;
import feature ;
# Compiler configuration. This definition will be used unless
# you already have defined some toolsets in your user-config.jam
# file.
if ! clang in [ feature.values <toolset> ]
{
    using clang ;
}
project : default-build <toolset>clang ;
# Python configuration
using python : 2.7 : /usr ;
# List of --with-<library> and --without-<library>
# options. If left empty, all libraries will be built.
# Options specified on the command line completely
# override this variable.
libraries =  ;
# These settings are equivivalent to corresponding command-line
# options.
option.set prefix : /usr/local ;
option.set exec-prefix : /usr/local ;
option.set libdir : /usr/local/lib ;
option.set includedir : /usr/local/include ;
# Stop on first error
option.set keep-going : false ;

Locations of g++ and clang++

jenkins-slave@tegra-ubuntu:~/workspace/Boost.AFIO Build POSIX_ARM_clang 3.4/boost-local$ whereis g++
g++: /usr/bin/g++ /usr/bin/X11/g++ /usr/share/man/man1/g++.1.gz
jenkins-slave@tegra-ubuntu:~/workspace/Boost.AFIO Build POSIX_ARM_clang 3.4/boost-local$ whereis clang++
clang++: /usr/bin/clang++ /usr/bin/X11/clang++ /usr/share/man/man1/clang++.1.gz

After bootstrapping with clang I also did a:

./b2 toolset=gcc libs/afio/build -d9 > debug.txt

... and have attached the output as a file which hopefully says what went wrong.

Let me know if you need anything else.

Niall

Niall Douglas — Tue, 29 Jul 2014 10:24:36 GMT

Ok attachments are limited to a pathetic 256Kb, so I sent the log to Google Drive:

https://drive.google.com/file/d/0B5QDPUNHLpKMNDJhM1ZoZXpCSms/edit?usp=sharing

Steven Watanabe — Tue, 23 Jan 2018 01:01:12 GMT

The reason this happens is:

clang imports gcc
gcc.jam calls feature.extend toolset : gcc ; at the top level.
build-system.jam attempts to autoconfigure toolsets based on whether the feature value is known. Therefore, a plain toolset=gcc will not trigger autoconfiguration if clang has been used.

Workarounds:

toolset=gcc-7.2.1 (or whatever the full version of gcc is)
add using gcc to user-config.jam.