When "module rec" is used, a file that can not be compiled is output by --sig option

[hafuu]

Repro steps

1. Compile following code with --sig option and generate signature file.

module rec Library1

[<Struct>]
type A = A of B

[<Struct>]
type B = B

2. Add the generated signature file to project.

Expected behavior

It generates the compilable signature.

Actual behavior

A compile error occurs: Unexpected keyword 'and' in signature file.

module Library1
[<StructAttribute ()>]
type A = | A of B
[<StructAttribute ()>]
and B = | B

Known workarounds

Edit the generated signature file manually as follows:

1. replace and to type for type B
2. add rec keyword after module keyword

module rec Library1
[<StructAttribute ()>]
type A = | A of B
[<StructAttribute ()>]
type B = | B

Related information

Windows, Visual Studio 2017, F# 4.1

[FunctionalFirst]

Isn't the issue that [<StructAttribute>] is in the wrong position? It should be after and.

[dsyme]

Covering problems with the --sig option by the single bug #393