lib.systems.elaborate: expose canExecute predicate over isCompatible

canExecute is like isCompatible, but also checks that the Kernels are
_equal_, i.e. that both platforms use the same syscall interface. This
is crucial in order to actually be able to execute binaries for the
other platform.

isCompatible is dropped, since it has changed semantically and there's
no use case left in nixpkgs.

1 files changed, 4 insertions, 2 deletions

diff --git a/lib/systems/default.nix b/lib/systems/default.nix
index e02890b1138..74f84914faa 100644
--- a/lib/systems/default.nix
+++ b/lib/systems/default.nix
@@ -34,8 +34,10 @@ rec {
       # Either of these can be losslessly-extracted from `parsed` iff parsing succeeds.
       system = parse.doubleFromSystem final.parsed;
       config = parse.tripleFromSystem final.parsed;
-      # Determine whether we are compatible with the provided CPU
-      isCompatible = platform: parse.isCompatible final.parsed.cpu platform.parsed.cpu;
+      # Determine whether we can execute binaries built for the provided platform.
+      canExecute = platform:
+        parse.isCompatible final.parsed.cpu platform.parsed.cpu
+        && final.parsed.kernel == platform.parsed.kernel;
       # Derived meta-data
       libc =
         /**/ if final.isDarwin              then "libSystem"