Make command executable of a checker selectable

[nordlow]

I'm missing a way to specify the executable of a command for a specific checker in my case the D checker. I would like to be able to switch between dmd and ldmd2.

As consequence of this I have to maintain to versions of my version of the D checker one; using dmd and one using ldmd2. This is not scalable.

[cpitclaudel]

We have flycheck-d-dmd-executable; does that work?

flycheck-d-dmd-executable is a variable defined in ‘flycheck.el’.

Its value is nil

The executable of the d-dmd syntax checker.

Either a string containing the name or the path of the
executable, or nil to use the default executable from the syntax
checker declaration.

The default executable is "dmd".

  This variable may be risky if used as a file-local variable.
  You can customize this variable.

[nordlow]

I don't find any references to flycheck-d-dmd-executable in flycheck.el, elpa version 20221112.1552.

[cpitclaudel]

What does C-h v flycheck-d-dmd-executable say?

[nordlow]

Ahh, C-h v flycheck-d-dmd-executable says

flycheck-d-dmd-executable is a variable defined in ‘flycheck.el’.

Its value is nil

The executable of the d-dmd syntax checker.

Either a string containing the name or the path of the
executable, or nil to use the default executable from the syntax
checker declaration.

The default executable is "dmd".

  This variable may be risky if used as a file-local variable.
  You can customize this variable.

but it doesn't have a source location. I see.

The end goal of this to set flycheck-d-dmd-executable to "ldmd2" (LDC) if that's available otherwise "dmd". Because ldmd2 is slightly faster at semantic checking than dmd.

I guess I should do that in a d-mode-hook lambda, right?

Am I right assuming that evaluating

(flycheck-define-checker X .. )

always results in

flycheck-X-executable

being defined?`

[cpitclaudel]

I guess I should do that in a d-mode-hook lambda, right?

Yep.

Am I right assuming that evaluating …

Correct, this is documented in https://www.flycheck.org/en/latest/user/syntax-checkers.html#change-syntax-checker-executables