Fails to compile on rustc >= 1.41.0

[transkatgirl]

When running the cargo install hyperbuild command, hyperbuild fails to compile if the user is using a recent version of rustc.

Output (rustc 1.41.0):

    Updating crates.io index
  Installing hyperbuild v0.0.45
   ...
   Compiling hyperbuild v0.0.45
error[E0716]: temporary value dropped while borrowed
   --> /home/katattakd/.cargo/registry/src/github.com-1ecc6299db9ec823/hyperbuild-0.0.45/src/spec/tag/omission.rs:149:86
    |
149 |   pub static CLOSING_TAG_OMISSION_RULES: Map<&'static [u8], &ClosingTagOmissionRule> = phf_map! {
    |  ______________________________________________________________________________________^
150 | |     b"li" => LI_CLOSING_TAG_OMISSION_RULE,
151 | |     b"dt" => DT_CLOSING_TAG_OMISSION_RULE,
152 | |     b"dd" => DD_CLOSING_TAG_OMISSION_RULE,
...   |
163 | |     b"th" => TH_CLOSING_TAG_OMISSION_RULE,
164 | | };
    | | ^
    | | |
    | | creates a temporary which is freed while still in use
    | |_temporary value is freed at the end of this statement
    |   cast requires that borrow lasts for `'static`
    |
    = note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)

error[E0716]: temporary value dropped while borrowed
   --> /home/katattakd/.cargo/registry/src/github.com-1ecc6299db9ec823/hyperbuild-0.0.45/src/spec/tag/whitespace.rs:51:91
    |
51  |   static TAG_WHITESPACE_MINIFICATION: Map<&'static [u8], &'static WhitespaceMinification> = phf_map! {
    |  ___________________________________________________________________________________________^
52  | |     // Content tags.
53  | |     b"address" => CONTENT,
54  | |     b"audio" => CONTENT,
...   |
159 | |     b"pre" => WHITESPACE_SENSITIVE,
160 | | };
    | | ^
    | | |
    | | creates a temporary which is freed while still in use
    | |_temporary value is freed at the end of this statement
    |   cast requires that borrow lasts for `'static`
    |
    = note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)

error[E0716]: temporary value dropped while borrowed
    --> /tmp/hyperbuild/debug/build/hyperbuild-eec30dbf52dbad28/out/gen_attrs.rs:7093:42
     |
7093 |   pub static ATTRS: AttrMap = AttrMap::new(phf::phf_map! {
     |  __________________________________________^
7094 | |     b"textrendering" => TEXTRENDERING_ATTR,
7095 | |     b"dx" => DX_ATTR,
7096 | |     b"restart" => RESTART_ATTR,
...    |
7493 | |     b"tablevalues" => TABLEVALUES_ATTR,
7494 | | });
     | | ^- temporary value is freed at the end of this statement
     | | |
     | |_creates a temporary which is freed while still in use
     |   cast requires that borrow lasts for `'static`
     |
     = note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for moreinfo)

error: aborting due to 3 previous errors

For more information about this error, try `rustc --explain E0716`.
error: failed to compile `hyperbuild v0.0.45`, intermediate artifacts can be found at `/tmp/hyperbuild`

Caused by:
  could not compile `hyperbuild`.

To learn more, run the command again with --verbose.

The above error is the same in newer versions of rust.

Ouput (rustc 1.40.0):

    Updating crates.io index
  Installing hyperbuild v0.0.45
   ...
   Compiling hyperbuild v0.0.45
    Finished release [optimized] target(s) in 2m 21s
  Installing /home/katattakd/.cargo/bin/hyperbuild
   Installed package `hyperbuild v0.0.45` (executable `hyperbuild`)

[wilsonzlin]

This seems to be rust-phf/rust-phf#187 which itself is caused by rust-lang/rust#70584. Not sure if we can work around the regression, will take a deeper look later.

[kornelski]

It looks like it won't be an easy fix in Rust, and it may take a while before it's fixed.

Could you make a release with a regular hashmap in the meantime?

[wilsonzlin]

I've switched all usages of phf over to lazy_static with the built in std::collections::Hash{Set,Map} data structures; everything seems to be working OK. It's now building on Rust 1.44.1.

The Python module was also not compiling due to PyO3 needing a newer Rust version, so now it's also working again.

Would like to revisit phf in the future if the bug gets fixed but I think the one-off initialisation costs are probably intangible.