https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106429
Bug ID: 106429
Summary: Building GCC is Inhibited on old Linux Distributions
due to the use of "#!/bin/bash"
Product: gcc
Version: 11.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: other
Assignee: unassigned at gcc dot gnu.org
Reporter: martin.vahi at softf1 dot com
Target Milestone: ---
Some newer version of C++_compiler is
needed to build applications that use some
newer C++ standard. By default old Linux distributions have
too old GCC versions, so a newer version of GCC needs to be
built before the applications that use newer C++ standard
can be built. Old Linux distributions are needed for
old hardware, because newer Linux distributions
do not always contain all the drivers for old hardware.
For example, in the case of openSUSE Linux, drivers
for old hardware are literally removed from the
package repositories of newer versions of the openSUSE Linux.
The paths at a "dependency graph" are:
the_use_of_old_hardware
--depends-on->
the_availability_of_drivers_for_that_old_hardware
--depends-on->
the_use_of_old_operating_system_distributions
--depends-on->
possibility_to_backport_applications_to_those_old_distributions
apps_that_use_newer_Cpp_standard
--depend-on->
some_newer_Cpp_compiler === GCC
--depends-during-buildtime-on->
availability_of_some_newer_version_of_Bash_on_PATH
--depends-on->
GCC_code_changes_that_are_described_in_this_bug_report
To build a newer version of GCC, some
newer version of Bash is at least sometimes required, because
the building of GCC, for example, version 11.2.0, includes
the execution of some Bash scripts. The default Bash
implementation tends to reside at the path "/bin/bash", but
one needs the newer version of the Bash on PATH only during
the building of the GCC. The classical solution in that
scenario is
export PATH="/path/to/the/newer/Bash/version/bin:$PATH"
which means that the new version of the Bash gets found before
the system default "/bin/bash" is found. However, if the GCC
build related Bash scripts start with
#!/bin/bash
in stead of
#!/usr/bin/env bash
then that kind of PATH based Bash executable override
does not work. The suggested and tested (GCC v. 11.2.0)
workaround is to use grep to find all Bash files that
start with the "#!/bin/bash" and replace the
"#!/bin/bash" with the "#!/usr/bin/env bash", except the file
gcc/contrib/repro_fail
because, for some nice amount of luck, leaving that one
to its "#!/bin/bash -eu" did not break anything.
The version of Bash that turned out to be too old
for building the GCC v.11.2.0 was
4.3.48(1)-release (x86_64-suse-linux-gnu)
and the version of Bash that was sufficiently new for building
GCC v.11.2.0 was Bash v.5.1
Thank You for reading this bug_report/comment.
