nix-super/doc/manual/rl-next/with-error-reporting.md

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---
synopsis: Better error reporting for `with` expressions
prs: 9658
---
`with` expressions using non-attrset values to resolve variables are now reported with proper positions.
Previously an incorrect `with` expression would report no position at all, making it hard to determine where the error originated:
```
nix-repl> with 1; a
error:
<borked>
at «none»:0: (source not available)
error: value is an integer while a set was expected
```
Now position information is preserved and reported as with most other errors:
```
nix-repl> with 1; a
error:
… while evaluating the first subexpression of a with expression
at «string»:1:1:
1| with 1; a
| ^
error: value is an integer while a set was expected
```