icu_datagen dependency conflicts when installing

[mhatzl]

There seem to be version conflicts between 1.2.0 and 1.3.0 versions.
Specifically, crates depending on zerovec versions 0.9.4 and 0.10.0.

Because versions are not pinned for icu_datagen as far as I can see,
internally some crates get set to 1.2.0 versions, while others to 1.3.0.
Trying to install icu_datagen using cargo install results in the following errors:

impl TrieValue for GeneralCategoryGroup {
    |                    ^^^^^^^^^^^^^^^^^^^^ the trait `zerovec::ule::AsULE` is not implemented for `props::GeneralCategoryGroup`
    |
    = help: the following other types implement trait `zerovec::ule::AsULE`:
              (A, B)
              (A, B, C)
              (A, B, C, D)
              (A, B, C, D, E)
              (A, B, C, D, E, F)
              NonZeroI8
              NonZeroU8
              Option<T>
            and 17 others
note: required by a bound in `TrieValue`

pub trait TrieValue: Copy + Eq + PartialEq + zerovec::ule::AsULE + 'static {
    |                                              ^^^^^^^^^^^^^^^^^^^ required by this bound in `TrieValue`

Note: There are many more errors, but the problem should be the same as far as I saw.

I assume that this gets resolved once icu_datagen version 1.3.0 is released.
However, this version conflict may happen again, because versions are now set to workspace = true,
and I don't know if that pins those versions.

[jedel1043]

This issue is also probably related: boa-dev/boa#3299

[sffc]

The 1.3 rollout took about 48 hours to finish; we did it over the weekend in an attempt to reduce the impact of errors like these. Can you confirm if this is still an issue?

Note:

• Installing ICU4X 1.3 should work
• ICU4X 1.2 should continue to work if it was created from a lockfile before 1.3 was released
• Unfortunately icu = "=1.2" does not resolve correctly using the default Cargo dependency resolver. To fix it, please manually make sure all icu crates are on 1.2 and zerovec is on 0.9 in the lockfile. You may need to run cargo update to pin specific versions of things.
• ICU4X 1.3 should not have this same type of problem because it uses ~ dependencies between components so installing icu =1.3 won't get a mix of 1.3 and 1.4 components, for example.

[sffc]

I published a detailed postmortem of what happened and why: #4093

Closing this issue because I don't see what else needs to be done. If anyone is still having problems, the postmortem is a good place to start.

[mhatzl]

Thanks for the fast reply.

Installing icu_datagen 1.3.0 worked for me.
However, installing 1.2.5 is not possible, because it takes 1.3.0 versions of icu crates internally.

Pinning icu crates in my own crate works.
I went through the lockfile until all icu crates had 1.2.0,
and depend on zerovec 0.9.x`.

Unfortunately, I cannot pin versions for icu_datagen,
because I install it as binary using cargo install.

I think to resolve this, you have to pin the versions on your side.
For icu_datagen this might be the best solution to prevent incompatibilities in the future.
As far as I understood, it is important to match icu_datagen with the versions used in a crate
to get correct providers.

In my project I currently only use the GraphemeSegmenter,
and with 1.3.0 there is the new() function so this is solved for me.

[sffc]

Yes, starting in 1.3 we pin the minor version which should help mitigate these types of problems.