Mirror of forum.nim-lang.org

14075 :: nimble: Passing additional params to the compiler

• nimzwo (orginal) [2026-07-21T15:35:30+02:00] view original

  In my code I have

  
  const VERSION {.strdefine.}: string = "unknown"
  Run

  If I pass -d:VERSION=0.1.0 everything works.

  I thought to myself, "I already have the version information in the Nimble file, so why should I repeat it?" and tried the following solution (which turned out not to be one):

  
  before build:
    switch("d", "VERSION=" & version)
  Run

  The task is evaluated:

  
   Attempting to execute hook buildBefore in /home/[…]
  Run

  But the parameter is not passed to the compiler.

  Any ideas on how I can pass the information to the compiler without writing a custom build task?

---

• daylinmorgan (orginal) [2026-07-21T18:00:59+02:00] view original

  nimble build adds the version into with a define flag of -d:NimblePkgVersion so you can change your const to that to get it.

---

• nimzwo (orginal) [2026-07-21T18:24:26+02:00] view original

  Thank you, works! :)

---

• nimzwo (orginal) [2026-07-21T21:38:18+02:00] view original

  The problem is solved, but out of curiosity: Does anyone know why my "solution"

  
  before build:
    switch("d", "VERSION=" & version)
  Run

  doesn't work?

  I assume a scope issue?

---

• daylinmorgan (orginal) [2026-07-22T00:41:30+02:00] view original

  What's under the before build essentially acts like it's own nimble task executed prior to the actual build step so the switch call there won't effect the build task which is handled separately by nimble

---