Travis: fail fast on install failures

[pdillinger]

Summary: A recent build continued with confusing results after failing
to "snap install cmake" so ensure failures in installs are fatal. Also
upgrade snapd before "snap install" to hopefully avoid this error:

error: cannot perform the following tasks:
- Mount snap "cmake" (513) (snap "cmake" assumes unsupported features: command-chain (try to update snapd and refresh the core snap))

Test Plan: watch Travis

[pdillinger]

For reference: https://travis-ci.org/github/facebook/rocksdb/jobs/716643910

[adamretter]

@pdillinger I am not sure this will help. If sudo snap install cmake --beta --classic exited with a non-zero code I think the build would have stopped, if it exited with a zero code, then I don't think adding exit $? will help you, as you will just get the same code... or did I miss something subtle?

[pdillinger]

Updated Travis link (I'm getting a bad one from GitHub): https://travis-ci.org/github/facebook/rocksdb/builds/716990002

It looks like two builds are failing the snap install.

The subtle thing is this:

$ bash -c 'cat doesnotexist; echo next_step'; echo $?
cat: doesnotexist: No such file or directory
next_step
0
$ bash -c 'cat doesnotexist || exit $?; echo next_step'; echo $?
cat: doesnotexist: No such file or directory
1
$

Unless using set -e or an operator like && or ||, the return code of a command will be ignored if followed by another command.

[adamretter]

Unless using set -e

Of course! Apologies, I am so used to always running scripts that include set -e

[pdillinger]

@adamretter Can you look at fixing the two builds that are completely failing the snap install? Feel free to create your own PR that includes this change.

[adamretter]

@pdillinger Yes, but I probably won't get to it until the weekend

[pdillinger]

@craigscott-crascit Is there a missing "snap refresh core" step we weren't told about or something? Our linux builds here are failing with

error: cannot perform the following tasks:
- Mount snap "cmake" (513) (snap "cmake" assumes unsupported features: command-chain (try to update snapd and refresh the core snap))

as in https://travis-ci.org/github/facebook/rocksdb/jobs/716990011

[craigscott-crascit]

@craigscott-crascit Is there a missing "snap refresh core" step we weren't told about or something? Our linux builds here are failing with

error: cannot perform the following tasks:
- Mount snap "cmake" (513) (snap "cmake" assumes unsupported features: command-chain (try to update snapd and refresh the core snap))

as in https://travis-ci.org/github/facebook/rocksdb/jobs/716990011

That's the first I've heard of this problem. After a quick bit of searching, it does seem likely that the core snap is not recent enough and needs to be refreshed. This issue seems to describe the problem reasonably well. Based on that, I would expect a sudo snap refresh core might fix it, but you'd have to try that and see.

[pdillinger]

This issue seems to describe the problem reasonably well. Based on that, I would expect a sudo snap refresh core might fix it, but you'd have to try that and see.

I think we have a winner with sudo apt-get install snapd to update snapd before running snap. Perhaps this subsumes snap refresh core. (?) Thanks.

[adamretter]

@pdillinger Another option might be to place snaps under addons. I think (but am not certain) that there might then be an update option. The travis syntax for snaps does not have much documentation, but perhaps the following might work:

addons:
  snaps:
    update: true
    packages:
      - cmake
         confinement:
           - classic
           - beta

[pdillinger]

Anything we add to Travis configuration now is better if it's more easily migrated to other CI systems.

[adamretter]

@pdillinger Okay understood. So the preference is to script things, rather than use the YAML config options?

[pdillinger]

@pdillinger Okay understood. So the preference is to script things, rather than use the YAML config options?

At least not spend extra time trying to use Travis-specific configs. (Approval?)

[facebook-github-bot]

@pdillinger has imported this pull request. If you are a Facebook employee, you can view this diff on Phabricator.

[facebook-github-bot]

@pdillinger merged this pull request in 327ddb7.