# Cannot install Concorde.jl on Mac OS M3

**URL:** <https://discourse.julialang.org/t/cannot-install-concorde-jl-on-mac-os-m3/125505>\
**Category:** General Usage\
**Tags:** question, package, mac, concorde, mac-m3\
**Created:** [February 3, 2025, 4:09pm UTC](https://discourse.julialang.org/t/cannot-install-concorde-jl-on-mac-os-m3/125505 "2025-02-03T16:09:42Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![mposs](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/mposs/32/21087_2.png) [@mposs](https://discourse.julialang.org/u/mposs)\
**Post date:** [February 3, 2025, 4:09pm UTC](https://discourse.julialang.org/t/cannot-install-concorde-jl-on-mac-os-m3/125505/1 "2025-02-03T16:09:42Z")

</div>

Hi

Would someone happen to know how to solve the problem when installing `Concorde.jl`:

```julia
(@v1.11) pkg> add Concorde
   Resolving package versions...
  No Changes to `~/.julia/environments/v1.11/Project.toml`
  No Changes to `~/.julia/environments/v1.11/Manifest.toml`
Precompiling project...
  ✗ Concorde
  0 dependencies successfully precompiled in 2 seconds. 238 already precompiled.
  1 dependency errored.
  For a report of the errors see `julia> err`. To retry use `pkg> precompile`

(@v1.11) pkg> build Concorde
    Building Concorde → `~/.julia/scratchspaces/44cfe95a-1eb2-52ea-b672-e2afdf69b78f/5d9f1b1a480235ffdd3c8ab8cab011aa9afe81af/build.log`
ERROR: Error building `Concorde`, showing the last 100 of log: 
x ./concorde/TOOLS/prob2tsp.c
x ./concorde/TOOLS/showres.c
...
x ./concorde/VERIFY/Makefile.in
x ./concorde/README
loading cache ./config.cache
checking host system type... Invalid configuration `darwin': machine `darwin' not recognized

checking for prespecified compiler options... no
checking for gcc... (cached) gcc
checking whether the C compiler (gcc -fPIC -O2 -g ) works... no
configure: error: installation or configuration problem: C compiler cannot create executables.
ERROR: LoadError: failed process: Process(`bash -c "CFLAGS='-fPIC -O2 -g' ./configure --with-qsopt=/Users/poss/.julia/packages/Concorde/VRfqN/deps/qsopt --host=darwin"`, ProcessExited(1)) [1]

```

It seems to be related to the M3 processor as I have the same error on another Mac with that processor, while the M2 I tried on could install the package properly.

It is related to my C compiler, but the latter works, despite the error `checking whether the C compiler (gcc -fPIC -O2 -g ) works... no`

```julia
poss@Mac-de-Michael ~ % gcc --version
Apple clang version 16.0.0 (clang-1600.0.26.6)
Target: arm64-apple-darwin24.1.0
Thread model: posix
InstalledDir: /Library/Developer/CommandLineTools/usr/bin

poss@Mac-de-Michael ~ % gcc -fPIC -O2 -g test.c

```

Best,

Michaël.

---

<div class="post-metadata">

**Author:** ![ufechner7](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/ufechner7/32/51363_2.png) [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Post date:** [February 3, 2025, 4:26pm UTC](https://discourse.julialang.org/t/cannot-install-concorde-jl-on-mac-os-m3/125505/2 "2025-02-03T16:26:15Z")

</div>

Related: [error installation on Mac OS (M3) · Issue #22 · chkwon/Concorde.jl · GitHub](https://github.com/chkwon/Concorde.jl/issues/22)

---

<div class="post-metadata">

**Author:** ![mposs](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/mposs/32/21087_2.png) [@mposs](https://discourse.julialang.org/u/mposs)\
**Post date:** [February 5, 2025, 3:24pm UTC](https://discourse.julialang.org/t/cannot-install-concorde-jl-on-mac-os-m3/125505/3 "2025-02-05T15:24:17Z")

</div>

I know, I posted it there. I was hoping that a larger audience would help.

---

<div class="post-metadata">

**Author:** ![ufechner7](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/ufechner7/32/51363_2.png) [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Post date:** [February 5, 2025, 5:03pm UTC](https://discourse.julialang.org/t/cannot-install-concorde-jl-on-mac-os-m3/125505/4 "2025-02-05T17:03:40Z")

</div>

There are probably not many users of Concorde.jl, (it has 13 likes), and not many of them will be owners of a Mac M3. But your problem seams to be related to `gcc`, and there might be people in this forum who now how to install the correct `gcc` on a Mac M3.