"Error while checking syntax automatically" when visiting a new file

[ysalmon]

Description

I get Error while checking syntax automatically when visiting a new file.

Repro steps

Please provide the steps required to reproduce the problem

1. Visit a new file /tmp/a.fsx.

Expected behavior

fsharp-mode loads and is ready to be used.

Actual behavior

fsharp-mode loads and gives the following error.

Debugger entered--Lisp error: (error "Buffer a.fsx has no process")
  signal(error ("Buffer a.fsx has no process"))
  #[257 "\300 \210\301�@�A\"\207" [flycheck-report-failed-syntax-check signal] 4 "\n\n(fn ERR)"]((error "Buffer a.fsx has no process"))
  funcall(#[257 "\300 \210\301�@�A\"\207" [flycheck-report-failed-syntax-check signal] 4 "\n\n(fn ERR)"] (error "Buffer a.fsx has no process"))
  flycheck-buffer()
  #[0 "\300 \207" [flycheck-buffer] 1 "\n\n(fn)"]()
  funcall(#[0 "\300 \207" [flycheck-buffer] 1 "\n\n(fn)"])
  flycheck-buffer-automatically()
  flycheck-perform-deferred-syntax-check()
  set-window-buffer(nil #<buffer a.fsx>)
  switch-to-buffer(#<buffer a.fsx>)
  find-file("/tmp/a.fsx" t)
  funcall-interactively(find-file "/tmp/a.fsx" t)

Known workarounds

none

Related information

• Operating system XUbuntu 16.04
• Branch
• Emacs version 25.3.2
• .NET Runtime, CoreCLR or Mono Version Mono JIT compiler version 5.12.0.226
• Performance information, links to performance testing scripts
• Flycheck version 31
• fsharp-mode version 20171021.431

[juergenhoetzel]

I can confirm this issue.

I added a flycheck predicate function in Pull Request: Add predicate function (WIP).

Unfortunately this broke integration tests: I need to check it out.

[juergenhoetzel]

Also working on better error reporting/diagnostics: Flycheck verify (WIP)

Any help is appreciated 🍻