Mirror of forum.nim-lang.org

6357 :: Checking the gcc/g++ versions used to compile nim program vs the dyn linked .so

• kaushalmodi (orginal) [2020-05-20T18:26:00+02:00] view original

  Hello,

  Today I came across this run time error when running a nim compiled program that dynamically linked with an external c++ library .so (let's call it external_lib_64.so)

  
  could not load: external_lib_64.so
  compile with -d:nimDebugDlOpen for more information
  Run

  So I compiled and ran the nim program with -d:nimDebugDlOpen and still that did not give any useful information.

  I knew that the external_lib_64.so was compiled using g++ 6.3.0. By a stroke of luck, it occurred to me that may be I should check the g++ version in my current environment where I was compiling the nim program .. and indeed it was different; it was g++ 8.4.0.

  Once I switch to g++ 6.3.0, re-compiled the nim program and ran it, that "could not load: external_lib_64.so" error went away and things once again ran fine as before.

  Questions to the community:

  • Should we need to match the g++ versions this way all the time? I thought that the compiled external_lib_64.so was "bulletproof" now that it was compiled. But apparently not?
  • @Araq Is it possible for the Nim compiler to detect this g++ version mismatch and throw a better error?

  This was using the latest stable nim 1.2.0.

---

• kaushalmodi (orginal) [2020-05-20T20:35:58+02:00] view original

  Turns out that this issue was because of some mixup in the LD_LIBRARY_PATH. Once was was fixed, the nim program built with even g++ 9.1.0 links fine with the external_lib_64.so built with g++ 6.3.0.

---