gcc<10 on M1 Mac

[VACCARI FRANCO]

Hi Chris,

thanks for the kind explanation!

Franco

> On 18 Jun 2021, at 17:16, Christopher Jones <jonesc at hep.phy.cam.ac.uk> wrote:
> 
> Hi,
> 
> Its highly unlikely you will ever get support for gcc<10 on arm. We only have support for 10 and 11 because we are using unreleased back ports of support from a development branch on arm for these two versions. The back port has not been done for anything older than 10, and is highly unlikely it ever will.
> 
> and yes, gcc5 does require newer libgccX versions. The reason for this is we want all gcc versions supported on a given machine to use the same runtime. So we make the most recent stable release the primary provider, for libgccN (N currently 11) and the older libgccN versions then only provide the additional older ABI versions needed for that specific compiler.
> 
> Chris
> 
>> On 18 Jun 2021, at 4:06 pm, VACCARI FRANCO <vaccari at units.it> wrote:
>> 
>> I’ve a temporary access to a new MacBook Air with M1 processor, to test on that Mac all our home made programs, mainly fortran. All external packages needed by our workflow were successfully installed (gnuplot, ImageMagick, gmt4 and many others), and I installed gcc11. 
>> 
>> Such modern compiler complains about some features in our code that are no longer supported, and fails to produce the executable. Of course one day we should update that code, but for the time being, and having to give back that Mac, I wanted to try with an older compiler. I installed gcc10 but that didn’t help.
>> 
>> I know that gcc8 works with our codes, so I tried to install that but failed.
>> 
>> The problem is that gcc8 requires libcc9, and that is marked as incompatible.
>> 
>> % sudo port install gcc8
>> --->  Computing dependencies for gcc8
>> The following dependencies will be installed: 
>> libgcc8
>> libgcc9
>> Continue? [Y/n]: 
>> --->  Fetching archive for libgcc9
>> --->  Attempting to fetch libgcc9-9.4.0_0.darwin_20.arm64.tbz2 from https://fra.de.packages.macports.org/libgcc9
>> --->  Attempting to fetch libgcc9-9.4.0_0.darwin_20.arm64.tbz2 from http://fco.it.packages.macports.org/libgcc9
>> --->  Attempting to fetch libgcc9-9.4.0_0.darwin_20.arm64.tbz2 from https://packages.macports.org/libgcc9
>> --->  Fetching distfiles for libgcc9
>> Error: gcc9 9.4.0 is not supported on Darwin 20 arm
>> Error: Failed to fetch libgcc9: incompatible OS X version
>> Error: See /opt/local/var/macports/logs/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lang_gcc9/libgcc9/main.log for details.
>> Error: Follow https://guide.macports.org/#project.tickets if you believe there
>> is a bug.
>> Error: Processing of port gcc8 failed
>> locadmin at eAir ~ %
>> 
>> Actually any version from 5 to 9 requires libcc9
>> 
>> sudo port install gcc5
>> --->  Computing dependencies for gcc5
>> The following dependencies will be installed: 
>> isl18
>> libgcc6
>> libgcc7
>> libgcc8
>> libgcc9
>> Continue? [Y/n]:
>> 
>> and therefore fails to install. 
>> 
>> gcc49 is a different story, as it’s clearly declared unsupported for Xcode 9 or greater:
>> 
>> sudo port install gcc49
>> Password:
>> --->  Fetching distfiles for gcc49
>> Error: building gcc49 is not supported with Xcode 9 or greater
>> Error: Failed to fetch gcc49: unsupported platform
>> Error: See /opt/local/var/macports/logs/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lang_gcc49/gcc49/main.log for details.
>> Error: Follow https://guide.macports.org/#project.tickets if you believe there
>> is a bug.
>> Error: Processing of port gcc49 failed
>> 
>> Is it really so that gcc9 and earlier will never be compatible with M1 Macs? And why libgcc9 is needed by gcc5?
>> 
>> Thanks
>> 
>> Franco
>> 
>> 
>