printAmbiguous (used by nix-instantiate --eval and nix-env) had a depth
parameter, but all callers passed INT_MAX, effectively disabling the
limit. The function relied on the C++ stack to eventually overflow,
which could cause uncontrolled SIGSEGV crashes on deeply nested
pre-forced structures.
Now printAmbiguous checks depth against max-call-depth (default 10000)
and throws StackOverflowError with a proper trace, consistent with
other recursive value traversal functions.
The function signature is updated to take EvalState& to access the
settings and throw proper errors. The depth parameter now counts up
from 0 instead of down from INT_MAX.
fd1ecfbfc8