`I/O error: _none_: No such file or directory` when using regex as `while` condition

[mediremi]

On v12.0.0-alpha.14, the following code triggers compiler error I/O error: _none_: No such file or directory:

while /foo/ {
  ()
}

[zth]

Is alpha.14 the first time that happens?

[mediremi]

I created a file runtime/TestFile.res with the above while loop and used the following script with git bisect run to find the first bad commit:

#!/bin/bash

make ninja && dune build && ./scripts/copyExes.js --compiler || exit $?

output=$(make lib 2>&1)

git restore lib

if echo "$output" | grep -q "I/O error"; then
    echo "$output"
    exit 1
else
    echo "$output"
    exit 0
fi

This issue first appears in commit 01ee097 (PR #7505)

[zth]

Thank you! I will take a look.