Improve error messaging around failed deployments (particularly of functions)

[nolessafool]

Currently when customers do something "interesting" with functions (there's a large class of things that count as interesting; see related issue: https://github.com/netlify/bitballoon/issues/1628), we give a very non-useful error message while failing the deploy:

10:37:50 AM: Failing build: Failed to deploy site
10:37:50 AM: failed during stage 'deploying site': Failed to execute deploy: Upload cancelled: submission-created

This comes from https://github.com/netlify/buildbot/blob/d1d46200977e9388ad296974ec8dacb61a1c47bc/bot/stage_deploy.go#L50

@calavera asserts that it should be improved here:

https://github.com/netlify/open-api/blob/master/go/porcelain/deploy.go#L389

if sharedErr.err != nil {
  return fmt.Errorf("Upload cancelled: %s -- %v", f.Name, sharedErr.err)

And maybe once that messaging is improved, buildbot can be changed to surface the reason rather than just that there was an inscrutable error.

[renschler]

I just got this message when I deployed my staging branch but no idea what it means
failed during stage 'deploying site': Failed to execute deploy: [PUT /deploys/{deploy_id}/functions/{name}][500] uploadDeployFunction default &{Code:0 Message:}

[vielmetti]

I also have an inscrutable error:

11:52:42 PM: failed during stage 'deploying site': Failed to execute deploy: Upload cancelled: memorials/usamemorial/usaimages/NYC_New_York_Liberty_Statue_and_Manhattan_from%20Aircraft.jpg

[vielmetti]

OK, third time a try.

The .shtml file in the home directory does not load, but nearly everything else works.

[Jones-S]

Hm I also got this unhelpful error:

10:33:52 PM: failed during stage 'deploying site': Failed to execute deploy: [PUT /deploys/{deploy_id}/functions/{name}][404] uploadDeployFunction default &{Code:0 Message:}

Are there a few things I could check my functions first? I tried them locally and there they work...

[kokokenada]

+1

8:04:41 PM: Failed to upload file: &{Name:graphql Sum:f41d58973535e276b493e3cc4d8bc0ac25204eb6b28ec843913958d8656d90a9 Runtime:js Size:<nil> Path: Buffer:0xc0002460c0}
8:04:41 PM: failed during stage 'deploying site': Failed to execute deploy: [PUT /deploys/{deploy_id}/functions/{name}][500] uploadDeployFunction default  &{Code:0 Message:}