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> Yes, but that doesn't change with rustc vs cargo > though; it's still a single rustc invocation to > compile all those files. When using Bazel instead of

> Yes, but that doesn't change with rustc vs cargo > though; it's still a single rustc invocation to > compile all those files. When using Bazel instead of Cargo the developer can split the build graph into much smaller crates (down to one per module if desired), and still treat the entire assembly as one package. I should emphasize that this is a limitation of Cargo, not rustc. rustc does just fine with big libraries, it's only Cargo that makes it difficult to write hundred-crate packages.

steveklabnik 6y ago
Ah, so you're not saying that you take the same project and port it from Cargo to Bazel and it somehow does less work, you're saying that it's easier to make projects with a larger number of smaller crates with Bazel than Cargo? That would be the bit I'm missing, Bazel and Cargo should invoke rustc the same amount of times per crate: once. Cargo doesn't change the compilation model of the language. (Sorry, I feel a bit dense here, but I am very curious to understand exactly. I haven't used Bazel a ton yet, but am very interested in it.)
- jmillikin 6y ago
  Yep, exactly. If I were building rust-fuse with Bazel I would probably split it into about 4 crates (fuse_kernel, fuse_io, protocol, server). This is what I tried to do in Cargo and gave up because of the crates.io packaging requirement.
  - steveklabnik 6y ago
    Gotcha. You can use path as a dependency if you also use the version as a dependency, and it’ll use the path locally but the version when you publish. Maybe that needs to be better documented and would have just fixed your issue. (This is described at https://doc.rust-lang.org/stable/cargo/reference/specifying-dependencies.html#specifying-path-dependencies https://doc.rust-lang.org/stable/cargo/reference/specifying-... )
    - jmillikin 6y ago
      That requires publishing the internal crates as separate entries in crates.io, if I understand correctly, which I don't want to do (see the final section on crates.io's packaging model). Ideally I could have a single crates.io package, with a single tarball, containing multiple crates. The internal crates would not be exposed to users, wouldn't have versions, wouldn't be on docs.rs, and so on.
      - steveklabnik 6y ago
        Yeah, that is true, it does. I do think that's an interesting idea. I'll have to mull on it. Thanks again. I've been thinking of a few things here, very interesting :)

steveklabnik 6y ago

Ah, so you're not saying that you take the same project and port it from Cargo to Bazel and it somehow does less work, you're saying that it's easier to make projects with a larger number of smaller crates with Bazel than Cargo? That would be the bit I'm missing, Bazel and Cargo should invoke rustc the same amount of times per crate: once. Cargo doesn't change the compilation model of the language. (Sorry, I feel a bit dense here, but I am very curious to understand exactly. I haven't used Bazel a ton yet, but am very interested in it.)

jmillikin 6y ago
Yep, exactly. If I were building rust-fuse with Bazel I would probably split it into about 4 crates (fuse_kernel, fuse_io, protocol, server). This is what I tried to do in Cargo and gave up because of the crates.io packaging requirement.
- steveklabnik 6y ago
  Gotcha. You can use path as a dependency if you also use the version as a dependency, and it’ll use the path locally but the version when you publish. Maybe that needs to be better documented and would have just fixed your issue. (This is described at https://doc.rust-lang.org/stable/cargo/reference/specifying-dependencies.html#specifying-path-dependencies https://doc.rust-lang.org/stable/cargo/reference/specifying-... )
  - jmillikin 6y ago
    That requires publishing the internal crates as separate entries in crates.io, if I understand correctly, which I don't want to do (see the final section on crates.io's packaging model). Ideally I could have a single crates.io package, with a single tarball, containing multiple crates. The internal crates would not be exposed to users, wouldn't have versions, wouldn't be on docs.rs, and so on.
    - steveklabnik 6y ago
      Yeah, that is true, it does. I do think that's an interesting idea. I'll have to mull on it. Thanks again. I've been thinking of a few things here, very interesting :)