[R-SIG-Mac] gfortran and macos 27

[Simon Urbanek]

Erich,

Homebrew compilers are incompatible with Apple's so generally it is not a godd idea to mix them.

There is a much easier solution, simply set

MACOSX_DEPLOYMENT_TARGET=28.0

in your environment (or you can use any other valid macOS version such as 15.0 or 26.0).

Cheers,
Simon



> On 4/10/2026, at 01:29, Erich Neuwirth <erich.neuwirth using univie.ac.at> wrote:
> 
> Pronblem solved.
> I had gcc from homebrew also installed.
> Putting
> 
> # GNU Fortran for Apple Silicon:
> # Work around the toolchain's invalid default macOS 18.0 target.
> FC      = /opt/gfortran/bin/gfortran -arch arm64
> F77     = /opt/gfortran/bin/gfortran -arch arm64
> FFLAGS  += -mmacosx-version-min=15.0
> FCFLAGS += -mmacosx-version-min=15.0
> 
> # OpenMP via Homebrew libomp
> CPPFLAGS += -I/opt/homebrew/opt/libomp/include -Xpreprocessor -fopenmp
> LDFLAGS  += -L/opt/homebrew/opt/libomp/lib -lomp
> 
> 
> in ~/.R/Makevars solved the problem. 
> 
> 
>> On Oct 3, 2026, at 2:06 PM, Erich Neuwirth <erich.neuwirth using univie.ac.at> wrote:
>> 
>> The problem seems to be buried in clang.
>> 
>> I reinstalled gfortran 
>> and ran the following test (recommended by perplexity)
>> 
>> ~ /opt/gfortran/bin/gfortran --version
>> 
>> cat > /tmp/check.f <<'EOF'
>>     program check
>>     print *, 'OK'
>>     end
>> EOF
>> 
>> /opt/gfortran/bin/gfortran -arch arm64 \
>> /tmp/check.f -o /tmp/check
>> 
>> /tmp/check
>> 
>> GNU Fortran (GCC) 14.2.0
>> Copyright (C) 2024 Free Software Foundation, Inc.
>> This is free software; see the source for copying conditions.  There is NO
>> warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
>> 
>> clang: error: invalid version number in '-mmacosx-version-min=18.0'
>> zsh: no such file or directory: /tmp/check
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>>> On Oct 3, 2026, at 12:38 PM, Erich Neuwirth <erich.neuwirth using univie.ac.at> wrote:
>>> 
>>> Hi Peter,
>>> I sett FFLAGS in .Renviron
>>>> Sys.getenv("FFLAGS")
>>> [1] "-mmacosx-version-min=26.0”
>>> 
>>> but when compiling still get the error
>>> clang: error: invalid version number in '-mmacosx-version-min=18.0'
>>> make: *** [qapsim.o] Error 1
>>> ERROR: compilation failed for package ‘qap’
>>> 
>>> 
>>> 
>>>> On Oct 2, 2026, at 1:43 PM, Peter Dalgaard <pdalgd using gmail.com> wrote:
>>>> 
>>>> FFLAGS=-mmacosx-version-min=26.0
>>> 
>>> _______________________________________________
>>> R-SIG-Mac mailing list
>>> R-SIG-Mac using r-project.org
>>> https://stat.ethz.ch/mailman/listinfo/r-sig-mac
>> 
>> _______________________________________________
>> R-SIG-Mac mailing list
>> R-SIG-Mac using r-project.org
>> https://stat.ethz.ch/mailman/listinfo/r-sig-mac
> 
> _______________________________________________
> R-SIG-Mac mailing list
> R-SIG-Mac using r-project.org
> https://stat.ethz.ch/mailman/listinfo/r-sig-mac
>