-mt compile dies in code generation: "linksign illegal"

I do not recall observing this failure before. Is it new?

It fails with naked "make", too.

> [ 94%] Built target seq-prog-schedrAKD
> //home/apex/apexgit/Ancillary/benchmks/benchmksPerf/kroneckerproduct/src/kroneckerproduct.sac:171:3: error: 
> => Pragma 'linksign' illegal: mappings allowed exclusively between parameters with identical types
> compilation failed while Preparing C code generation, 1 error(s).
> make[2]: *** [kroneckerproduct/src-mt_pth/CMakeFiles/mt_pth-module-kroneckerproduct.dir/build.make:74: lib/host/mt-pth/libkroneckerproductMod.so] Error 129
> make[2]: Target 'kroneckerproduct/src-mt_pth/CMakeFiles/mt_pth-module-kroneckerproduct.dir/build' not remade because of errors.
> make[1]: *** [CMakeFiles/Makefile2:410: kroneckerproduct/src-mt_pth/CMakeFiles/mt_pth-module-kroneckerproduct.dir/all] Error 2
> //home/apex/apexgit/Ancillary/benchmks/benchmksPerf/kroneckerproduct/src/kroneckerproduct.sac:171:3: error: 
> => Pragma 'linksign' illegal: mappings allowed exclusively between parameters with identical types
> compilation failed while Preparing C code generation, 1 error(s).
> make[2]: *** [kroneckerproduct/src-mt_pth/CMakeFiles/mt_pth-prog-kroneckerproduct.dir/build.make:78: lib/host/mt-pth/libkroneckerproductMod.so] Error 129
> make[2]: Target 'kroneckerproduct/src-mt_pth/CMakeFiles/mt_pth-prog-kroneckerproduct.dir/build' not remade because of errors.
> make[1]: *** [CMakeFiles/Makefile2:384: kroneckerproduct/src-mt_pth/CMakeFiles/mt_pth-prog-kroneckerproduct.dir/all] Error 2
> make[1]: Target 'all' not remade because of errors.
> make: *** [Makefile:136: all] Error 2
> make: Target 'default_target' not remade because of errors.

> apex@boa:~/apexgit/Ancillary/benchmks/benchmksPerf/build$

 sac2c -V
sac2c 1.3.3-MijasCosta-677-g0587e
build-type: RELEASE
built-by: "sac" at 2021-06-23T15:20:00