huh libffi is acting funny in openbsd

$ l $(nix-build -A pkgsCross.gnu64.libffi)/lib
total 84K
dr-xr-xr-x  1 root root  88 jan  1  1970 .
dr-xr-xr-x  1 root root  16 jan  1  1970 ..
-r-xr-xr-x  2 root root 957 jan  1  1970 libffi.la
lrwxrwxrwx 13 root root  15 jan  1  1970 libffi.so -> libffi.so.8.2.0
lrwxrwxrwx 13 root root  15 jan  1  1970 libffi.so.8 -> libffi.so.8.2.0
-r-xr-xr-x  2 root root 70K jan  1  1970 libffi.so.8.2.0

$ l $(nix-build -A pkgsCross.x86_64-freebsd.libffi)/lib
total 56K
dr-xr-xr-x  1 root root  88 jan  1  1970 .
dr-xr-xr-x  1 root root   6 jan  1  1970 ..
-r-xr-xr-x  2 root root 971 jan  1  1970 libffi.la
lrwxrwxrwx 13 root root  15 jan  1  1970 libffi.so -> libffi.so.8.2.0
lrwxrwxrwx 13 root root  15 jan  1  1970 libffi.so.8 -> libffi.so.8.2.0
-r-xr-xr-x  2 root root 43K jan  1  1970 libffi.so.8.2.0

$ l $(nix-build -A pkgsCross.x86_64-openbsd.libffi)/lib
total 48K
dr-xr-xr-x 1 root root  46 jan  1  1970 .
dr-xr-xr-x 1 root root   6 jan  1  1970 ..
-r-xr-xr-x 2 root root 966 jan  1  1970 libffi.la
-r-xr-xr-x 2 root root 43K jan  1  1970 libffi.so.10.0