Hi, I am having the following warning when compiling any fortran example (currently on main, but it’s been going on for a little while) on a ARM mac. *******************Error detected during compile or link!******************* See http://www.mcs.anl.gov/petsc/documentation/faq.html /opt/HPC/petsc-main/src/snes/tutorials ex5f ********************************************************* mpif90 -Wl,-bind_at_load -Wl,-multiply_defined,suppress -Wl,-multiply_defined -Wl,suppress -Wl,-commons,use_dylibs -Wl,-search_paths_first -Wl,-no_compact_unwind -ffree-line-length-none -fallow-argument-mismatch -fPIC -g -ffree-line-length-none -fallow-argument-mismatch -fPIC -g -I/opt/HPC/petsc-main/include -I/opt/HPC/petsc-main/bigsur-gcc10.2-arm64-reallybasic-g/include -I/opt/X11/include ex5f.F90 -Wl,-rpath,/opt/HPC/petsc-main/bigsur-gcc10.2-arm64-reallybasic-g/lib -L/opt/HPC/petsc-main/bigsur-gcc10.2-arm64-reallybasic-g/lib -Wl,-rpath,/opt/X11/lib -L/opt/X11/lib -Wl,-rpath,/opt/homebrew/Cellar/mpich/3.4.1_2/lib -L/opt/homebrew/Cellar/mpich/3.4.1_2/lib -Wl,-rpath,/opt/homebrew/Cellar/gcc/10.2.0_4/lib/gcc/10/gcc/aarch64-apple-darwin20/10.2.1 -L/opt/homebrew/Cellar/gcc/10.2.0_4/lib/gcc/10/gcc/aarch64-apple-darwin20/10.2.1 -Wl,-rpath,/opt/homebrew/Cellar/gcc/10.2.0_4/lib/gcc/10 -L/opt/homebrew/Cellar/gcc/10.2.0_4/lib/gcc/10 -lpetsc -llapack -lblas -lX11 -lc++ -ldl -lmpifort -lmpi -lpmpi -lgfortran -lemutls_w -lm -lc++ -ldl -o ex5f warning: (arm64) could not find object file symbol for symbol ___muldc3 Fortran example src/snes/tutorials/ex5f run successfully with 1 MPI process For reference, here is how I configured petsc: ./configure --CFLAGS='-Wimplicit-function-declaration' --FFLAGS="-ffree-line-length-none -fallow-argument-mismatch" --with-debugging=1 --with-shared-libraries=1 --with-x11=1 It looks like this symbol is referenced in: sfpack.o SiMini:petsc-main (main)$ grep -ri muldc3 bigsur-gcc10.2-arm64-reallybasic-g/* Binary file bigsur-gcc10.2-arm64-reallybasic-g/lib/libpetsc.3.015.0.dylib matches Binary file bigsur-gcc10.2-arm64-reallybasic-g/lib/libpetsc.3.015.dylib matches bigsur-gcc10.2-arm64-reallybasic-g/lib/petsc/conf/check.log:warning: (arm64) could not find object file symbol for symbol ___muldc3 Binary file bigsur-gcc10.2-arm64-reallybasic-g/lib/libpetsc.dylib matches Binary file bigsur-gcc10.2-arm64-reallybasic-g/obj/vec/is/sf/impls/basic/sfpack.o matches SiMini:petsc-main (main)$ nm bigsur-gcc10.2-arm64-reallybasic-g/obj/vec/is/sf/impls/basic/sfpack.o | grep muldc3 U ___muldc3 Any idea? Blaise -- A.K. & Shirley Barton Professor of Mathematics Adjunct Professor of Mechanical Engineering Adjunct of the Center for Computation & Technology Louisiana State University, Lockett Hall Room 344, Baton Rouge, LA 70803, USA Tel. +1 (225) 578 1612, Fax +1 (225) 578 4276 Web http://www.math.lsu.edu/~bourdin