"No module named ... is imported" message is a bit misleading with qualified imports (#14225) · Issues · Glasgow Haskell Compiler / GHC

"No module named ... is imported" message is a bit misleading with qualified imports

It seems that the No module named ... is imported message produced in response to out-of-scope identifiers doesn't account for qualified imports. For instance,

$ ghci
GHCi, version 8.2.1: http://www.haskell.org/ghc/  :? for help
Loaded GHCi configuration from /home/ben/.ghci
λ> import qualified Data.Maybe as M
λ> M.fromJusr

<interactive>:2:1: error:
    Not in scope: ‘M.fromJusr’
    Perhaps you meant ‘M.fromJust’ (imported from Data.Maybe)
    No module named ‘M’ is imported.
λ>

I suppose there is the question of whether we consider M to be a "module" here; I would argue that I imported it and therefore the message is at very least a bit misleading.

Trac metadata

Trac field	Value
Version	8.2.1
Type	Bug
TypeOfFailure	OtherFailure
Priority	low
Resolution	Unresolved
Component	Compiler
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system
Architecture

It seems that the `No module named ... is imported` message produced in response to out-of-scope identifiers doesn't account for qualified imports. For instance,

```
$ ghci
GHCi, version 8.2.1: http://www.haskell.org/ghc/  :? for help
Loaded GHCi configuration from /home/ben/.ghci
λ> import qualified Data.Maybe as M
λ> M.fromJusr

<interactive>:2:1: error:
    Not in scope: ‘M.fromJusr’
    Perhaps you meant ‘M.fromJust’ (imported from Data.Maybe)
    No module named ‘M’ is imported.
λ> 
```

I suppose there is the question of whether we consider `M` to be a "module" here; I would argue that I imported it and therefore the message is at very least a bit misleading.

<details><summary>Trac metadata</summary>

| Trac field             | Value        |
| ---------------------- | ------------ |
| Version                | 8.2.1        |
| Type                   | Bug          |
| TypeOfFailure          | OtherFailure |
| Priority               | low          |
| Resolution             | Unresolved   |
| Component              | Compiler     |
| Test case              |              |
| Differential revisions |              |
| BlockedBy              |              |
| Related                |              |
| Blocking               |              |
| CC                     |              |
| Operating system       |              |
| Architecture           |              |

</details>