Heroku Deployment fails, gmp needed

[beanieboi]

$ git push heroku 
Counting objects: 51, done.
Delta compression using up to 4 threads.
Compressing objects: 100% (47/47), done.
Writing objects: 100% (51/51), 7.26 KiB | 0 bytes/s, done.
Total 51 (delta 23), reused 0 (delta 0)
remote: Compressing source files... done.
remote: Building source:
remote: 
remote: -----> Fetching set buildpack https://github.com/crystal-lang/heroku-buildpack-crystal.git... done
remote: -----> Crystal app detected
remote: -----> Installing Crystal (0.18.4 due to .crystal-version file)
remote: -----> Installing Dependencies
remote: Updating https://github.com/sdogruyol/kemal.git
remote: Updating https://github.com/luislavena/radix.git
remote: Updating https://github.com/jeromegn/kilt.git
remote: Updating https://github.com/sdogruyol/spec-kemal.git
remote: Updating https://github.com/mperham/sidekiq.cr.git
remote: Updating https://github.com/mperham/crystal-redis.git
remote: Updating https://github.com/ysbaddaden/pool.git
remote: Updating https://github.com/miketheman/statsd.cr.git
remote: Updating https://github.com/beanieboi/aws-signer.cr.git
remote: Installing kemal (0c46bd65da9092c4e2d1776c13730eb63fbb6bc9)
remote: Installing radix (0.3.0)
remote: Installing kilt (0.3.3)
remote: Installing spec-kemal (8c0d4268b9ae2b8e7aadfe290006c28060bb61c8)
remote: Installing sidekiq (9248c0f0469d1ead010080a3acf2d6fa4e22c7d5)
remote: Installing redis (744bac8ec708e996ab020b79cbebdb17e28f6e23)
remote: Installing pool (0.2.3)
remote: Installing statsd (917c948e182b26150e124fa84a30ec4518635bf0)
remote: Installing aws_signer (bae4215fb96a074f1cc0e5cb07f116d0f93744ab)
remote: -----> Compiling src/lighthouse.cr (auto-detected from shard.yml)
remote: Deprecation: The build command was renamed to compile and will be removed in a future version.
remote: /usr/bin/ld: cannot find -lgmp
remote: collect2: error: ld returned 1 exit status
remote: Error: execution of command failed with code: 1: `cc -o "/tmp/build_48475e7b877277455138ed66882ee136/app" "${@}"  -rdynamic  -lgmp -lz `pkg-config --libs libssl || printf %s '-lssl -lcrypto'` `pkg-config --libs libcrypto || printf %s '-lcrypto'` -lpcre -lm -lgc -lpthread /tmp/crystal/src/ext/libcrystal.a -levent -lrt -ldl -L/usr/lib -L/usr/local/lib`
remote: 
remote:  !     Push rejected, failed to compile Crystal app
remote: 
remote: Verifying deploy...
remote: 
remote: !   Push rejected to codeship-lighthouse-cr.
remote: 
To https://git.heroku.com/codeship-lighthouse-cr.git
 ! [remote rejected] master -> master (pre-receive hook declined)
error: failed to push some refs to 'https://git.heroku.com/codeship-lighthouse-cr.git'

it looks like gmp is a new dependency in Crystal 0.18? i remember that the deployment worked fine with 0.17.

[bcardiff]

libgmp is there since 0.16 at least.
using "big" of the std requires gmp which is not installed by default.
related crystal-lang/homebrew-crystal#15 (comment)

Are you using big_* explicitly in your code?

We might need to work something similar to https://github.com/begriffs/heroku-buildpack-ghc to get gmp installed by default in heroku just in case :-(

Or finding/building a buildpack to install gmp, but I am not sure that will work.

[beanieboi]

i added sidekiq as a dependency and sidekiq uses big_float (https://github.com/mperham/sidekiq.cr/blob/master/src/sidekiq/core_ext.cr#L1). this means no Sidekiq on Heroku :(

[beanieboi]

@mperham do you think you can remove the patch, it looks like this got fixed in a newer version of crystal.

[mperham]

Yep, this was needed pre-0.18 but no more, removed from master.

[beanieboi]

@mperham thanks so much!

[bcardiff]

Isn't it nice when the "fix" is to delete code? :-)

Let's leave this open until gmp or other runtime dependencies are added in the buildpack.

[beanieboi]

@bcardiff i worked on a couple of buildpacks before, i will try to add gmp to the buildpack, to remove this restriction.

[bacongobbler]

@beanieboi if you can write a fixture + unit test that covers this problem after #12 is merged, it should be easy to confirm the fix works.

[beanieboi]

@bacongobbler sure, will look into it.