[petsc-dev] Fortran macOS Linkage Warning

[Satish Balay]

ok - gfortran is using:

> COLLECT_GCC_OPTIONS='-o' '/var/folders/9w/7dlszmmn6q1gd5yf3r9n79bc0000gn/T/petsc-dk9aiv7x/config.compilers/conftest' '-v' '-Wall' '-ffree-line-length-0' '-Wno-unused-dummy-argument' '-g' '-mmacosx-version-min=11.2.0' '-asm_macosx_version_min=11.2' '-shared-libgcc' '-mtune=core2'


Likely -mmacosx-version-min=11.2.0 option is causing this issue. I do not know why brew gfortran is using this option.

Satish


On Mon, 15 Feb 2021, Jacob Faibussowitsch wrote:

> I can reproduce the warning compiling just that simple code you listed. This is the compile command:
> 
> mkdir -p build && gfortran -c -o ./build/conftest.o conftest.F90 && gcc -o ./build/libconftest.dylib ./build/conftest.o -dynamiclib -undefined dynamic_lookup && rm -rf ./build
> 
> And error:
> ld: warning: object file (./build/conftest.o) was built for newer macOS version (11.2) than being linked (11.0)
> 
> Note I recently uninstalled and reinstalled command line tools too, which does not seem to have fixed it.
> 
> Best regards,
> 
> Jacob Faibussowitsch
> (Jacob Fai - booss - oh - vitch)
> Cell: (312) 694-3391
> 
> > On Feb 15, 2021, at 11:30, Satish Balay <balay at mcs.anl.gov> wrote:
> > 
> > Here is the compile command and the warning:
> > 
> >>>>>>> 
> > ===== Checking linker
> > Executing: gfortran -c -o /var/folders/9w/7dlszmmn6q1gd5yf3r9n79bc0000gn/T/petsc-dk9aiv7x/config.setCompilers/conftest.o -I/var/folders/9w/7dlszmmn6q1gd5yf3r9n79bc0000gn/T/petsc-dk9aiv7x/config.setCompilers   /var/folders/9w/7dlszmmn6q1gd5yf3r9n79bc0000gn/T/petsc-dk9aiv7x/config.setCompilers/conftest.F90 
> > Successful compile:
> > Source:
> >      function foo(a)
> >      real:: a,x,bar
> >      common /xx/ x
> >      x=a
> >      foo = bar(x)
> >      end
> > Executing: gcc  -o /var/folders/9w/7dlszmmn6q1gd5yf3r9n79bc0000gn/T/petsc-dk9aiv7x/config.setCompilers/libconftest.dylib  -dynamiclib -single_module -undefined dynamic_lookup -multiply_defined suppress  /var/folders/9w/7dlszmmn6q1gd5yf3r9n79bc0000gn/T/petsc-dk9aiv7x/config.setCompilers/conftest.o 
> > Possible ERROR while running linker:
> > stderr:
> > ld: warning: object file (/var/folders/9w/7dlszmmn6q1gd5yf3r9n79bc0000gn/T/petsc-dk9aiv7x/config.setCompilers/conftest.o) was built for newer macOS version (11.2) than being linked (11.0)
> >          Accepted FC PIC code without compiler flag
> >          =============================================================================================
> > <<<<<<
> > 
> > Its likely due to the way brew built gfortran. You can try compiling a simple test code and see if you can reproduce this warning.
> > 
> > There is a related issue at:
> > 
> > https://github.com/spack/spack/issues/21644
> > 
> > Satish
> > 
> > 
> > On Sat, 13 Feb 2021, Jacob Faibussowitsch wrote:
> > 
> >> Hello All,
> >> 
> >> I’ve been getting these warnings for weeks, at first I figured it was due to gfortran brew package not being updated for Big Sur, but since it has persisted through a few gfortran brew updates I’m thinking it may be petsc related. This is on clean build on master.
> >> 
> >> ld: warning: object file (master-arch-darwin-c-debug/obj/sys/classes/bag/f2003-src/fsrc/bagenum.o) was built for newer macOS version (11.2) than being linked (11.0)
> >> ld: warning: object file (master-arch-darwin-c-debug/obj/sys/f90-src/fsrc/f90_fwrap.o) was built for newer macOS version (11.2) than being linked (11.0)
> >> ld: warning: object file (master-arch-darwin-c-debug/obj/sys/objects/f2003-src/fsrc/optionenum.o) was built for newer macOS version (11.2) than being linked (11.0)
> >> ld: warning: object file (master-arch-darwin-c-debug/obj/sys/fsrc/somefort.o) was built for newer macOS version (11.2) than being linked (11.0)
> >> ld: warning: object file (master-arch-darwin-c-debug/obj/sys/f90-mod/petscsysmod.o) was built for newer macOS version (11.2) than being linked (11.0)
> >> 
> >> Best regards,
> >> 
> >> Jacob Faibussowitsch
> >> (Jacob Fai - booss - oh - vitch)
> >> Cell: (312) 694-3391
> >> 
> 
>