Missing "v1.0.0:shard.yml"

[mamantoha]

Hi there.

There is an issue with installing some shards after updating to Crystal 0.34.0.

Steps to reproduce:

• Create new lib (e.g. crystal init lib test_redis)
• Add dependency to shard.yml

  dependencies:
    redis:
      github: stefanwille/crystal-redis

• Run shards

Output:

Missing "v1.0.0:shard.yml" for "redis"

Previously it took the latest version from the master branch.

shards --version
Shards 0.10.0 [4091ac5] (2020-04-06)

crystal --version
Crystal 0.34.0 [4401e90f0] (2020-04-06)

LLVM: 8.0.0
Default target: x86_64-unknown-linux-gnu

[straight-shoota]

I noticed this error, too.

The reason is that redis@1.0.0 doesn't provide a shard.yml but shards tries to read all older releases to figure out which dependencies match. A version that doesn't provide a shard.yml should just be ignored instead of failing. I think that's how this worked before 0.10.0.

A quick fix is to pin the shard to a specific version. For example

dependencies:
  redis:
    github: stefanwille/crystal-redis
    version: 2.5.3

This avoids shards trying to read shard.yml of oder releases.

[waj]

Shards could also assume no dependencies for a tag without shard.yml.
@straight-shoota do you foresee any conflict by adopting that behavior?

[straight-shoota]

I'm not sure whether this would necessarily create a conflict. But treating a tag as a shards version when the fundamental shard.yml file is missing completely, doesn't seem like a good idea.
Especially if other versions of the same repo include a shard.yml.

[waj]

I find quite strange to just ignore the tags. We should at least provide a warning or error if that version is selected. These versions exist probably from pre-shards era and not used so often anyway.

[straight-shoota]

Sure, making it an error should be fine. I just meant it shouldn't be a version you can actually use.

[waj]

But why not just a warning? What's the critical issue we're trying to avoid?

[straight-shoota]

Okay let's be clear:

• In the example case form the OP, there should be no mention at all about missing shard.yml in v1.0.0 because this is not relevant to the user. This is simply a legacy issue and needs neither a warning nor an error. Either the version is simply not considered for dependency resolution, or it is silently accepted. Verbose logging could inform about that.
• If you explicitly ask for a version that doesn't have a shard.yml (for example add version: 1.0.0 to redis dependency), I'm not sure what should happen. Maybe it should show a warning.

Btw. shardbox knows about 84 releases with missing `shard.yml`

         shard         |                               versions
-----------------------+----------------------------------------------------------------------
 prax-cr               | 0.4.1, 0.4.0, 0.2.0, 0.6.1, 0.5.0, 0.3.0, 0.5.1, 0.7.0, 0.4.2, 0.6.0
 crul                  | 0.0.1b, 0.3.1, 0.0.1a, 0.1.0, 0.2.0, 0.2.1, 0.3.0
 html-pipeline         | 0.2.1, 0.2.0, 0.3.1, 0.2.2, 0.0.1, 0.3.0, 0.1.0
 crustache~gitlab      | 0.1.1, 0.1.0, 0.3.2, 0.3.0, 0.2.1, 0.2.0, 0.3.1
 crustache~jwaldrip    | 0.2.0, 0.3.2, 0.1.0, 0.1.1, 0.2.1, 0.3.0, 0.3.1
 crustache             | 0.1.1, 0.1.0, 0.3.2, 0.3.1, 0.2.0, 0.2.1, 0.3.0
 amethyst              | 0.1, 0.1.7, 0.0.2, 0.0.7, 0.1.3
 power_assert          | 0.2.2, 0.2.3, 0.2.0, 0.2.1
 mysql~waterlink       | 0.0.2, 0.1.0, 0.0.1
 redis~maiha           | 1.0.1, 1.0.0, 1.1.0
 redis                 | 1.0.1, 1.1.0, 1.0.0
 mpp                   | 0.1.0, 0.2.1, 0.2.0
 memcached             | 0.0.1, 0.1.0
 shards                | 0.2.0, 0.1.0
 emoji                 | 0.0.1, 0.1.0
 cryload               | 0.0.2
 minitest~ragmaanir    | 0.1.0
 timecop~taylorfinnell | 0.0.2
 spellout              | 1.0.0
 timecop~waterlink     | 0.0.2
 cltk                  | 0.0.2
 minitest              | 0.1.0
 mocks                 | 0.1.0
 host_meta             | 0.1.0
 web_finger            | 0.1.0
 amatista              | 0.3.1
 icr~TechMagister      | HEAD
(27 rows)

[waj]

Agree with the first point. For the second, I'm writing a fix to show a warning when the version gets selected, explicitly or with a version expression. I think Shards should be as annoying as possible until the problem gets fixed, but not introduce blocking issues unnecessary.

Shardbox is becoming an essential tool for this project. I think I'm going to ask you access to that database or install an instance myself 😉

[straight-shoota]

I should probably make database exports available. 👍