Migrate to the 2021 edition

[yozhgoor]

Hello there!

This PR migrate the project to the 2021 edition using cargo fix --edition

[yozhgoor]

I wanted to fix an error message when I try to migrate from the 2018 edition to the 2021 in a project but I don't see it on the fork

The error message look like this:

error[E0391]: cycle detected when computing when `topojson::geometry::Value` has a significant destructor
  --> /home/user/.cargo/registry/src/github.com-1ecc6299db9ec823/topojson-0.5.0/src/geometry.rs:21:1
   |
21 | pub enum Value {
   | ^^^^^^^^^^^^^^
   |
   = note: ...which immediately requires computing when `topojson::geometry::Value` has a significant destructor again
note: cycle used when computing when `topojson::geometry::Geometry` has a significant destructor
  --> /home/user/.cargo/registry/src/github.com-1ecc6299db9ec823/topojson-0.5.0/src/geometry.rs:87:1
   |
87 | pub struct Geometry {
   | ^^^^^^^^^^^^^^^^^^^

For more information about this error, try `rustc --explain E0391`.

[yozhgoor]

Cool! :rocket: What do you think about the error message? Do you mind if I open an issue about that to merge this PR?

[lnicola]

I've never seen that error before and I didn't really get the specifics. Are you saying that:

• you have a 2018 edition crate that depends on toopjson
• you wanted to upgrade it to the 2021edition
• after upgrading, you're getting that compiler error
• you still get the error after a cargo clean?

My understanding is that dependencies should keep working when you change editions. If I got it right, can you put together a simple test case? I tried to reproduce it with an empty project with the topojson dependency, but it builds fine. Which compiler version are you using?

[yozhgoor]

rustc 1.60.0 at the moment. You get it right, I also tried on a empty project and no problem too. I'm gonna investigate the issue on my side to see if I can find something useful. It probably comes from my implementation. I'll keep you update in that case, thanks for your time!

[lnicola]

This is a small change, can someone from the project review and/or merge it?

I think I have bors rights, but I've only contributed to other parts of GeoRust and I don't know the maintainers here.

[lnicola]

In the meanwhile, it might even make sense to go to the 2021 edition. Some people would prefer to bump the version to 0.6 here, but it's not clear-cut. Personally, I don't think MSRV changes are semver-breaking.

[lnicola]

bors r=pjsier,lnicola,urschrei

[bors[bot]]

:lock: Permission denied

Existing reviewers: click here to make lnicola a reviewer

[urschrei]

I don't have access to bors on this repo for some reason

[michaelkirk]

@frewsxcv seems to have bors access. Can you add some other folks?

(https://github.com/georust/topojson/pull/6#issuecomment-439750356)

[frewsxcv]

done

[michaelkirk]

bors r=pjsier,lnicola,urschrei

[bors[bot]]

Configuration problem: bors.toml: not found

[urschrei]

bors try

[urschrei]

bors r=pjsier,lnicola,urschrei

[bors[bot]]

Timed out.

[lnicola]

I think we need different workflow job names in bors.toml:

[urschrei]

bors try

[bors[bot]]

try

Already running a review

[urschrei]

bors r-

[urschrei]

bors try

[bors[bot]]

try

Already running a review

[urschrei]

¯_(ツ)_/¯

[lnicola]

See https://github.com/georust/topojson/blob/master/bors.toml.

status needs to list the job names that bors was to wait for. The CI here uses different job names, not ci result.

[urschrei]

I just tried to change that: https://github.com/georust/topojson/blob/master/.github/workflows/test.yml#L20

[lnicola]

bors retry

[bors[bot]]

try

Already running a review

[lnicola]

bors r-

[cecton]

error[E0391]: cycle detected when computing when `topojson::geometry::Value` has a significant destructor
  --> /home/user/.cargo/registry/src/github.com-1ecc6299db9ec823/topojson-0.5.0/src/geometry.rs:21:1
   |
21 | pub enum Value {
   | ^^^^^^^^^^^^^^
   |
   = note: ...which immediately requires computing when `topojson::geometry::Value` has a significant destructor again
note: cycle used when computing when `topojson::geometry::Geometry` has a significant destructor
  --> /home/user/.cargo/registry/src/github.com-1ecc6299db9ec823/topojson-0.5.0/src/geometry.rs:87:1
   |
87 | pub struct Geometry {
   | ^^^^^^^^^^^^^^^^^^^

For more information about this error, try `rustc --explain E0391`.

I had this issue too when I migrated to 2021 on a private project... I think (not sure) I solved it by adding Box on types of fields that was recursive.

So let's say I have an enum A that is recursive (some variants have Box<A> in their fields). Then I have a struct B that uses the enum A in a field. I added Box on the field in struct B to fix the issue struct B { field_a: Box<A> }.

I'm really not certain about this, it's been a long time.

[urschrei]

bors try

[bors[bot]]

try

Already running a review

[urschrei]

bors try

[bors[bot]]

try

Already running a review

[urschrei]

I have no idea why bors is being like this, but I'm happy to manually merge this now that CI has passed, in the interest of moving forward. @cecton thanks for the info: there doesn't seem to be an issue on current stable – it may have been transient.

[bors[bot]]

try

Timed out.

[cecton]

I have no idea why bors is being like this,

clearly he's bored, you're not treating it well

@cecton thanks for the info: there doesn't seem to be an issue on current stable – it may have been transient.

all the work i did for nothing :weary: (good thing I don't remember)