build fails because of missing crate

[gilligan]

Description: I was trying to use crate2nix for hydra-cli but it fails because it can't find some crates.

---

• Expected: The build succeeds as it does with cargo build
• Actual: The build fails because some crate is missing
• How to reproduce:

$ git clone https://github.com/nlewo/hydra-cli
$ git checkout test-crate2nix
$ nix-build -A hydra-cli

Error Output

Building src/lib.rs (flate2)                                                                                                                                   
Running rustc --crate-name flate2 src/lib.rs --crate-type lib -C opt-level=3 -C codegen-units=4 --edition 2015 -C metadata=0cab654bef -C extra-filename=-0cab65
4bef --cfg feature="miniz_oxide" --cfg feature="rust_backend" --out-dir target/lib --emit=dep-info,link -L dependency=target/deps --extern crc32fast=/nix/store
/3m24x66k8w7snjsdzsmcgprahqvn5ija-rust_crc32fast-1.2.0/lib/libcrc32fast-093f96a061.rlib --extern libc=/nix/store/fcsgigv8c5d74403ak65r4rpzi834743-rust_libc-0.2
.62/lib/liblibc-68f9c48770.rlib --cap-lints allow --color always 
unpacking sources                                                                                  
unpacking source archive /nix/store/95n075cbnpnm7ys0b3bdkrv8rid5x27n-crossbeam-queue-0.1.2.tar.gz                                         
unpacking sources                                                                    
source root is crossbeam-queue-0.1.2.tar.gz                                                                                                                   
unpacking source archive /nix/store/85p4a11g26c17xwc7v63v1zkp9qq70d9-getrandom-0.1.11.tar.gz 
error[E0463]: can't find crate for `miniz_oxide`                                                           
   --> src/ffi.rs:469:5                                            
    |                                                                                                                                                         
469 |     extern crate miniz_oxide;                                                  
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^ can't find crate

error: aborting due to previous error

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

[gilligan]

FWIW when i changed feature="rust_backend" to default that one worked but then it fails elsewhere..

[TMVector]

@gilligan out of curiosity, what did you mean by "when i changed feature="rust_backend" to default"? How I would I do the same to reproduce later errors?

[kolloch]

Thank you very much for reporting this! Sorry, that I didn't have much time last week.

If I read the comments right, this is also about the rand crate renames?

I created an issue for this #22. Help is appreciated. How can we make this work on the nix level?

[kolloch]

Do I take it that the rename PR fixes this? Please reopen if it doesn't.