With the latest build of cctools in conda-forge, using Clang or GFortran with an absolute path to the output target results in a broken binary.

Here is a simple reproducer for Fortran code. With a test file sanitycheckf.f90:

program main; print *, "Fortran compilation is working."; end program

And using the arm64-apple-darwin20.0.0-gfortran compiler, I see the following on an arm64 Macbook:

% rm sanitycheckf
% gfortran build/meson-private/sanitycheckf.f90 -o /Users/rgommers/code/scipy/sanitycheckf       
% ./sanitycheckf 
zsh: killed     ./sanitycheckf
% rm sanitycheckf
% gfortran build/meson-private/sanitycheckf.f90 -o sanitycheckf 
% ./sanitycheckf                                              
 Fortran compilation is working.

Showing that a simple absolute path is enough to trigger the problem.

On conda-forge/cctools-and-ld64-feedstock#50 (comment) @erykoff observed the same issue with a hello world C program and Clang.

Copying the produced binary (cp sanitycheckf sanitycheckf2 && cp sanitycheckf2 sanitycheckf) makes the problem go away. Downgrading to an older cctools version also made the problem go away.