# Problems deploying SWIPL + sCASP on GCP

**URL:** <https://swi-prolog.discourse.group/t/problems-deploying-swipl-scasp-on-gcp/7254>\
**Category:** Help!\
**Created:** [February 19, 2024, 9:01pm UTC](https://swi-prolog.discourse.group/t/problems-deploying-swipl-scasp-on-gcp/7254 "2024-02-19T21:01:55Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Gauntlet173](https://yyz2.discourse-cdn.com/free1/user_avatar/swi-prolog.discourse.group/gauntlet173/32/3778_2.png) [@Gauntlet173](https://swi-prolog.discourse.group/u/Gauntlet173)\
**Post date:** [February 19, 2024, 9:01pm UTC](https://swi-prolog.discourse.group/t/problems-deploying-swipl-scasp-on-gcp/7254/1 "2024-02-19T21:01:55Z")

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I’m getting an error `existence_error(procedure, '/'(scasp, 2))` when running SWIPL and sCASP on a Google Cloud Run service, but I’m not able to recreate the same problem when I run the same code locally inside a docker container built from the same repository. As far as I can tell from the logs, everything is being installed correctly inside the container, so there’s no obvious reason that the scasp predicate would not be present in the container on GCP.

I’m sort of at a loss as to how to troubleshoot that, just wondering if anyone has run into similar strange issues with installing modules on a container hosted in a GCP or similar environment.

Thanks!

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**Author:** ![jan](https://yyz2.discourse-cdn.com/free1/user_avatar/swi-prolog.discourse.group/jan/32/4_2.png) [@jan](https://swi-prolog.discourse.group/u/jan)\
**Post date:** [February 20, 2024, 8:06am UTC](https://swi-prolog.discourse.group/t/problems-deploying-swipl-scasp-on-gcp/7254/2 "2024-02-20T08:06:13Z")

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Hard to tell without any clue on how this is built or deployed. My first step would be to run check/0 at the startup in the container. That might tell you where the undefined predicate comes from. Another is to wrap the main goal into catch\_with\_backtrace/3 and make sure the `library(prolog_stack)` is loaded. That should result in a backtrace.