# \[SOLVED\] OPAM External solver failure

**URL:** <https://discuss.ocaml.org/t/solved-opam-external-solver-failure/2332>\
**Category:** Ecosystem\
**Tags:** opam\
**Created:** [July 24, 2018, 2:29pm UTC](https://discuss.ocaml.org/t/solved-opam-external-solver-failure/2332 "2018-07-24T14:29:38Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![basus](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ocaml.org/basus/32/29_2.png) [@basus](https://discuss.ocaml.org/u/basus)\
**Post date:** [July 24, 2018, 2:29pm UTC](https://discuss.ocaml.org/t/solved-opam-external-solver-failure/2332/1 "2018-07-24T14:29:38Z")

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I keep getting the following error when trying to do an `opam upgrade`:

```auto

[WARNING] External solver failed:
# opam-version 1.2.2
# os darwin
# command aspcud /Users/basus/.opam/log/solver-in-91011-4bcc67 /Users/basus/.opam/log/solver-out-91011-dd682e -count(down),-count(removed),-notuptodate(solution),-sum(solution,version-lag),-count(new)
# path /Users/basus/src/conveyances
# exit-code 1
# env-file /Users/basus/.opam/log/log-91011-ccabea.env
# stdout-file /Users/basus/.opam/log/log-91011-ccabea.out
# stderr-file /Users/basus/.opam/log/log-91011-ccabea.err
### stderr ###
# ERROR: grounder returned with non-zero exit status

[ERROR] External solver failure, please fix your installation and check /Users/basus/.opam/config and variable $OPAMEXTERNALSOLVER.

```

The `.out` file is empty and the corresponding `.err` file simply says : `ERROR: grounder returned with non-zero exit status`. Even trying to reinstall the switch does not help. I’m running OPAM 1.2.2 on macOS High Sierra.

---

<div class="post-metadata">

**Author:** ![AltGr](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ocaml.org/altgr/32/4220_2.png) [@AltGr](https://discuss.ocaml.org/u/AltGr)\
**Post date:** [July 30, 2018, 8:23am UTC](https://discuss.ocaml.org/t/solved-opam-external-solver-failure/2332/2 "2018-07-30T08:23:07Z")

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Solved [here](https://github.com/ocaml/opam/issues/3484), for reference