fix(tvix/eval): don't force lambda arg in map, mapAttrs & genList r/7735

It is pretty pointless to force the function argument if we are going to
use a suspended call later since forcing the function may fail in ways
that are not covered by Catchables (non-recoverable errors, infinite
recursions). From this, it kind of seems as if using #[catch] is never
correct and should be replaced by #[lazy]. Also we should probably try
to come up with more test cases for stuff where laziness gets us out of
the jam as an equivalent to the catchable tests for nonrecoverable
errors.

Fixes b/386.

Change-Id: Ia926df4ac1b440ec430403ab7b40924a0c97221b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/11153
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Autosubmit: sterni <sternenseemann@systemli.org>

1 files changed, 8 insertions, 0 deletions

diff --git a/tvix/eval/src/tests/tvix_tests/eval-okay-builtins-mapAttrs-function-strictness.nix b/tvix/eval/src/tests/tvix_tests/eval-okay-builtins-mapAttrs-function-strictness.nix
new file mode 100644
index 0000000000..2946d6de17
--- /dev/null
+++ b/tvix/eval/src/tests/tvix_tests/eval-okay-builtins-mapAttrs-function-strictness.nix
@@ -0,0 +1,8 @@
+let
+  self =
+    let
+      s = builtins.mapAttrs self.f { a = 1; b = 2; };
+    in
+    { f = _: x: x; } // s;
+in
+self