Compression feature breaks incremental builds

[djmarcin]

When using the compression feature, incremental builds where only the embedded files change do not trigger a rebuild. This is most obvious when using both compression and debug-embed.

I think this is because include_bytes! has special logic in the compiler to add a dependency and trigger rebuilds when the file changes, but include_flate! does not (and does not use include_bytes! internally).

[pyrossh]

Do you think this can be fixed/added in the include_flate! repo? As that would help any other projects using it. I'm guessing its not going that easy though.

[djmarcin]

There is an unstable feature that would allow it to track the file, but that would mean that using it would require nightly. https://github.com/rust-lang/rust/issues/99515

There is another workaround which involves assigning include_bytes! to an unused temporary but I’m not sure if that defeats the point of the compression by including it in the binary again or if it gets optimized out.

I wanted to report it here in case it would be prudent to add a warning that compression should only be used with clean builds or something until this can be fixed.

[pyrossh]

Yeah maybe we can update the readme. Will do it thanks.

[pyrossh]

Done. thanks.

[osiewicz]

Hey, it looks like this issue was addressed within include_flate itself recently? https://github.com/SOF3/include-flate/commit/4cf6b8e1ece726e16e1fd5a7f7e9e2237726bf9f

[pyrossh]

Ahh nice. Will update include-flate to 0.2.0 and remove the note.

[pyrossh]

Release v6.8.0 with the changes thanks @djmarcin @osiewicz.

[pyrossh]

Seems like it breaks the tests,

   Compiling rust-embed v6.8.0 (/Users/pyrossh/Code/rust-embed)
error: couldn't read /Users/pyrossh/Code/rust-embed//Users/pyrossh/Code/rust-embed/examples/public/images/doc.txt: No such file or directory (os error 2)
 --> tests/lib.rs:4:10
  |
4 | #[derive(RustEmbed)]
  |          ^^^^^^^^^
  |
  = note: this error originates in the macro `include_bytes` which comes from the expansion of the derive macro `RustEmbed` (in Nightly builds, run with -Z macro-backtrace for more info)

error: couldn't read /Users/pyrossh/Code/rust-embed//Users/pyrossh/Code/rust-embed/examples/public/images/flower.jpg: No such file or directory (os error 2)
 --> tests/lib.rs:4:10
  |
4 | #[derive(RustEmbed)]
  |          ^^^^^^^^^
  |
  = note: this error originates in the macro `include_bytes` which comes from the expansion of the derive macro `RustEmbed` (in Nightly builds, run with -Z macro-backtrace for more info)

error: couldn't read /Users/pyrossh/Code/rust-embed//Users/pyrossh/Code/rust-embed/examples/public/images/llama.png: No such file or directory (os error 2)
 --> tests/lib.rs:4:10
  |
4 | #[derive(RustEmbed)]
  |          ^^^^^^^^^
  |
  = note: this error originates in the macro `include_bytes` which comes from the expansion of the derive macro `RustEmbed` (in Nightly builds, run with -Z macro-backtrace for more info)

error: couldn't read /Users/pyrossh/Code/rust-embed//Users/pyrossh/Code/rust-embed/examples/public/index.html: No such file or directory (os error 2)
 --> tests/lib.rs:4:10
  |
4 | #[derive(RustEmbed)]
  |          ^^^^^^^^^
  |
  = note: this error originates in the macro `include_bytes` which comes from the expansion of the derive macro `RustEmbed` (in Nightly builds, run with -Z macro-backtrace for more info)

error: couldn't read /Users/pyrossh/Code/rust-embed//Users/pyrossh/Code/rust-embed/examples/public/main.css: No such file or directory (os error 2)
 --> tests/lib.rs:4:10
  |
4 | #[derive(RustEmbed)]
  |          ^^^^^^^^^
  |
  = note: this error originates in the macro `include_bytes` which comes from the expansion of the derive macro `RustEmbed` (in Nightly builds, run with -Z macro-backtrace for more info)

error: couldn't read /Users/pyrossh/Code/rust-embed//Users/pyrossh/Code/rust-embed/examples/public/main.js: No such file or directory (os error 2)
 --> tests/lib.rs:4:10
  |
4 | #[derive(RustEmbed)]
  |          ^^^^^^^^^
  |
  = note: this error originates in the macro `include_bytes` which comes from the expansion of the derive macro `RustEmbed` (in Nightly builds, run with -Z macro-backtrace for more info)

error: could not compile `rust-embed` (test "lib") due to 6 previous errors

[osiewicz]

These paths look like a concatenation of absolute and relative path; I believe include-flate 0.2 explicitly dropped support for absolute paths, so perhaps they changed the API to accept only relative paths? https://github.com/SOF3/include-flate/commit/4d79700ba0a67b764700f591c0ab8635b6ba5bac

[pyrossh]

Fixed again in v6.8.1. Thanks.