Failing build with html5ever

[nuxeh]

Hi,

I'm having issues building with nix for crates with html5ever as a dependency.

https://github.com/nuxeh/crate2nix-test is an example repo with a default.nix generated by crate2nix 0.3.0-beta.0

The build seems to fail due to the missing extern crate, new_debug_unreachable:

error[E0463]: can't find crate for `debug_unreachable`
  --> src/lib.rs:10:1
   |
10 | extern crate debug_unreachable;
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ can't find crate

error: aborting due to previous error

For more information about this error, try `rustc --explain E0463`.

I've done some debugging but haven't been able to track down what the issue is. The build order differs, and besides that, the only difference i can see is that the rustc invocations differ in the output directory, compared with building with cargo:

Running rustc --crate-name futf src/lib.rs --crate-type lib -C opt-level=3 -C codegen-units=4 --edition 2015 -C metadata=7a698c1757 -C extra-filename=-7a698c1757 --out-dir target/lib --emit=dep-info,link -L dependency=target/deps --extern mac=/nix/store/bjcw280v92drg93d89zpkh997xljfl89-rust_mac-0.1.1/lib/libmac-c77a325080.rlib --extern new_debug_unreachable=/nix/store/qz5ffk70ibllz27awjnpp9v7rbcrxnq5-rust_new_debug_unreachable-1.0.3/lib/libnew_debug_unreachable-6437ae92c0.rlib --cap-lints allow --color always

--out-dir target/lib

Running `rustc --crate-name futf /home/ed/.cargo/registry/src/github.com-1ecc6299db9ec823/futf-0.1.4/src/lib.rs --color never --crate-type lib --emit=dep-info,link -C debuginfo=2 -C metadata=b65310681f505b82 -C extra-filename=-b65310681f505b82 --out-dir /home/ed/git/url-bot-rs/target/debug/deps -L dependency=/home/ed/git/url-bot-rs/target/debug/deps --extern mac=/home/ed/git/url-bot-rs/target/debug/deps/libmac-705013cbc305aca9.rlib --extern debug_unreachable=/home/ed/git/url-bot-rs/target/debug/deps/libdebug_unreachable-6884cd8b03bd695e.rlib --cap-lints allow`

--out-dir /home/ed/git/url-bot-rs/target/debug/deps

Thanks.

[kolloch]

Thanks for reporting this including a repo for reproducing the error and your detailed report!

I see a further difference:

--extern new_debug_unreachable=/nix/store/qz5ffk70ibllz27awjnpp9v7rbcrxnq5-rust_new_debug_unreachable-1.0.3/lib/libnew_debug_unreachable-6437ae92c0.rlib

vs

--extern debug_unreachable=/home/ed/git/url-bot-rs/target/debug/deps/libdebug_unreachable-6884cd8b03bd695e.rlib

Which explains why the library is available as debug_unreachable in the second case...

I'll investigate further...

[kolloch]

I suspect this is down to the fact that the crate is called new_debug_unreachable but the library debug_unreachable: https://github.com/mbrubeck/rust-debug-unreachable/blob/fork/Cargo.toml#L12-L14

[lib]
name = "debug_unreachable"
path = "src/lib.rs"

That is exposed in the cargo metadata output:

{
        "id": "futf 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
        "dependencies": [
          "mac 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
          "new_debug_unreachable 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)"
        ],
        "deps": [
          {
            "name": "mac",
            "pkg": "mac 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)"
          },
          {
            "name": "debug_unreachable",
            "pkg": "new_debug_unreachable 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)"
          }
        ],
        "features": []
      },

  {
      "name": "new_debug_unreachable",
      "version": "1.0.3",
      "id": "new_debug_unreachable 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
      "license": "MIT",
      "license_file": null,
      "description": "panic in debug, intrinsics::unreachable() in release (fork of debug_unreachable)",
      "source": "registry+https://github.com/rust-lang/crates.io-index",
      "dependencies": [],
      "targets": [
        {
          "kind": [
            "lib"
          ],
          "crate_types": [
            "lib"
          ],
          "name": "debug_unreachable",
          "src_path": "/home/peter/.cargo/registry/src/github.com-1ecc6299db9ec823/new_debug_unreachable-1.0.3/src/lib.rs",
          "edition": "2015"
        },
        {
          "kind": [
            "example"
          ],
          "crate_types": [
            "bin"
          ],
          "name": "simple",
          "src_path": "/home/peter/.cargo/registry/src/github.com-1ecc6299db9ec823/new_debug_unreachable-1.0.3/examples/simple.rs",
          "edition": "2015"
        },
        {
          "kind": [
            "test"
          ],
          "crate_types": [
            "bin"
          ],
          "name": "check",
          "src_path": "/home/peter/.cargo/registry/src/github.com-1ecc6299db9ec823/new_debug_unreachable-1.0.3/tests/check.rs",
          "edition": "2015"
        }
      ],
// ...

Now I need to investigate on how to make this work with buildRustCrate. Renaming the crate alone does not work but we can additionally provide an explicit source:

diff --git a/default.nix b/default.nix
index de58004..50fb7ea 100644
--- a/default.nix
+++ b/default.nix
@@ -235,10 +235,14 @@ rec {
             };
         "new_debug_unreachable 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)"
             = buildRustCrate {
-                crateName = "new_debug_unreachable";
+                crateName = "debug_unreachable";
                 version = "1.0.3";
                 edition = "2015";
                 sha256 = "1lxbd0n9gwvzg41bxiij0c28g1sp1jhp4h1rh10qisc8viyhsdj0";
+                src = builtins.fetchGit {
+                    url = "https://github.com/mbrubeck/rust-debug-unreachable";
+                    rev = "e374f6990882871d62ddcd1d9964b26ac50c5c7e";
+                };
                 libPath = "src/lib.rs";
                 authors = [
                     "Matt Brubeck <mbrubeck@limpet.net>"

(Obviously, the source should be fetched from crates.io instead, this is just a proof of concept.)

With this fix, I run into a similar problem with the utf_8 crate, though, which exports the utf8 library.

I'll try to fix this today -- if that doesn't work out, you'll probably need to wait until at least next weekend :(

[kolloch]

Does this solve your problem?

Please continue to send me such awesome bug reports, @nuxeh!

[nuxeh]

@kolloch it does appear to have solved the problem for the test repo, but for my own project, https://github.com/nuxeh/url-bot-rs, there's still the following error, this time for cssparser:

Building src/lib.rs (cssparser)
Running rustc --crate-name cssparser src/lib.rs --crate-type lib -C opt-level=3 -C codegen-units=4 --edition 2015 -C metadata=15b8375349 -C extra-filename=-15b8375349 --out-dir target/lib --emit=dep-info,link -L dependency=target/deps --extern cssparser_macros=/nix/store/8yl9hhivlcpr1q485d9h9kywwlxiia91-rust_cssparser-macros-0.3.5/lib/libcssparser_macros-57e42b786a.so --extern dtoa_short=/nix/store/4v891ffdrzxa2yv547mn3dcdc7iqvak0-rust_dtoa-short-0.3.2/lib/libdtoa_short-77d68b4a44.rlib --extern itoa=/nix/store/adhj88qqyin8zf9bd10xqv1dsizv3bhr-rust_itoa-0.4.3/lib/libitoa-a6f76c7f27.rlib --extern matches=/nix/store/j3laann65lzck6lyg9bpjk7gjw9ihk2k-rust_matches-0.1.8/lib/libmatches-47ddbc585f.rlib --extern phf=/nix/store/qcvaa9ya6vgcrpmmyiq042a8jpb4niid-rust_phf-0.7.24/lib/libphf-95b8a51ebb.rlib --extern procedural_masquerade=/nix/store/rwzpk2qq99bkvr83hckj8akf6xq84dfy-rust_procedural-masquerade-0.1.6/lib/libprocedural_masquerade-e6f18a276f.rlib --extern smallvec=/nix/store/nh1i2602n3nphcrxmznrjbnvmpn747iq-rust_smallvec-0.6.9/lib/libsmallvec-99bacd0cdd.rlib --cap-lints allow -L /build/cssparser-0.24.1.tar.gz/target/build/cssparser.out --cfg rustc_has_pr45225 --color always
error: extern location for cssparser_macros does not exist: /nix/store/8yl9hhivlcpr1q485d9h9kywwlxiia91-rust_cssparser-macros-0.3.5/lib/libcssparser_macros-57e42b786a.so

error[E0463]: can't find crate for `cssparser_macros`
  --> src/lib.rs:73:14
   |
73 | #[macro_use] extern crate cssparser_macros;
   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ can't find crate

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0463`.
builder for '/nix/store/dj2mwhaqg6yma100xscp0rx0s43h7zi8-rust_cssparser-0.24.1.drv' failed with exit code 1
cannot build derivation '/nix/store/378wm523mf1mscvbqc7vjhvy8n3hmdj8-rust_url-bot-rs-0.2.0.drv': 1 dependencies couldn't be built
error: build of '/nix/store/378wm523mf1mscvbqc7vjhvy8n3hmdj8-rust_url-bot-rs-0.2.0.drv' failed

So as far as i can tell, not out of the woods yet.

Thanks for looking at this, i'll certainly report anything else i find :)

[nuxeh]

Hmm, cssparser-macros seems to be a sub-crate within cssparser, I wonder if that has anything to do with this.

I can't imagine that that's uncommon, but it looks slightly suspicious for a normal Cargo project to me, just lib.rs and Cargo.toml.

https://github.com/servo/rust-cssparser/tree/master/macros

[kolloch]

I created #5 for this.