Mirror of forum.nim-lang.org

8697 :: Could not run program which compiling with static linked lib

• geohuz (orginal) [2021-12-09T19:25:07+01:00] view original

  I'm trying to static link postgresql libpq with my program which connects to postgresql server, here is my docker file:

  
  FROM nimlang/nim:alpine
  
  RUN apk add --no-cache postgresql-dev
  
  ENTRYPOINT ["sh", "-c"]
  Run

  build:

  
  docker build  -t pgcompile .
  Run

  compile:

  
  docker run --rm -v (pwd):/mypgclient  -w /mypgclient pgcompile "nim c --passL:'-static' --passL:'-lpq' -d:release -d:danger -d:nimDebugDlOpen mypgclient"
  Run

  This compiles successfully, but I got error:

  
  Dynamic loading not supported
  could not load: libpq.so(.5|)
  Run

  What is the problem?

---

• treeform (orginal) [2021-12-09T19:35:28+01:00] view original

  I don't think you can just statically link libpq.so, you need libpg.a - static library file. I don't think apk add postgresql-dev gives you that, I think it only gives you the dynamically linked one. For static linking you probably would have to build libpq.a yourself from source. Libpq is a huge library you will also have to figure out two to deal with its dependencies: ssl, crypto zlib, iconv, ... I think it's going to take a long time to figure out.

  If you are using docker why care about static linking?

---

• geohuz (orginal) [2021-12-09T20:20:24+01:00] view original

  I'm using docker to cross compile from my macbookpro.

---

• Yardanico (orginal) [2021-12-10T00:25:18+01:00] view original

  In Nim you also need to do --dynlibOverride:"pq" to tell Nim to not try to dynamically load a library if the wrapper uses the dynlib pragma, see the bottom of the https://nim-lang.org/docs/manual.html#foreign-function-interface-dynlib-pragma-for-import section.

---