warning: unexpected cfg condition name: pgrx_embed

[ccleve]

I just upgraded to Rust 1.84, blew away my .pgrx directory and redid cargo pgrx init, cargo clean, and then cargo pgrx run. I'm getting the error above. I have version 0.12.9 installed.

To duplicate the error, upgrade Rust as I did, run cargo pgrx new tester, switch to the tester directory, and then cargo pgrx run. I got this output:

ccleve@MacBookPro tester % cargo pgrx run
       Using DefaultFeature("pg13") and `pg_config` from /Users/ccleve/.pgrx/13.18/pgrx-install/bin/pg_config
    Building extension with features pg13
     Running command "/Users/ccleve/.rustup/toolchains/stable-aarch64-apple-darwin/bin/cargo" "build" "--lib" "--features" "pg13" "--no-default-features" "--message-format=json-render-diagnostics"
   Compiling proc-macro2 v1.0.93

... bunch of files omitted ...

   Compiling pgrx v0.12.9
   Compiling tester v0.0.0 (/Users/ccleve/dev/pg/tester)
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 28.90s
  Installing extension
     Copying control file to /Users/ccleve/.pgrx/13.18/pgrx-install/share/postgresql/extension/tester.control
     Copying shared library to /Users/ccleve/.pgrx/13.18/pgrx-install/lib/postgresql/tester.so
  Discovered 1 SQL entities: 0 schemas (0 unique), 1 functions, 0 types, 0 enums, 0 sqls, 0 ords, 0 hashes, 0 aggregates, 0 triggers
  Rebuilding pgrx_embed, in debug mode, for SQL generation with features pg13
   Compiling tester v0.0.0 (/Users/ccleve/dev/pg/tester)
warning: unexpected `cfg` condition name: `pgrx_embed`
 --> src/bin/pgrx_embed.rs:1:1
  |
1 | ::pgrx::pgrx_embed!();
  | ^^^^^^^^^^^^^^^^^^^^^
  |
  = help: expected names are: `clippy`, `debug_assertions`, `doc`, `docsrs`, `doctest`, `feature`, `fmt_debug`, `miri`, `overflow_checks`, `panic`, `proc_macro`, `relocation_model`, `rustfmt`, `sanitize`, `sanitizer_cfi_generalize_pointers`, `sanitizer_cfi_normalize_integers`, `target_abi`, `target_arch`, `target_endian`, `target_env`, `target_family`, `target_feature`, `target_has_atomic`, `target_has_atomic_equal_alignment`, `target_has_atomic_load_store`, `target_os`, `target_pointer_width`, `target_thread_local`, `target_vendor`, `test`, `ub_checks`, `unix`, and `windows`
  = help: consider using a Cargo feature instead
  = help: or consider adding in `Cargo.toml` the `check-cfg` lint config for the lint:
           [lints.rust]
           unexpected_cfgs = { level = "warn", check-cfg = ['cfg(pgrx_embed)'] }
  = help: or consider adding `println!("cargo::rustc-check-cfg=cfg(pgrx_embed)");` to the top of the `build.rs`
  = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg/cargo-specifics.html> for more information about checking conditional configuration
  = note: `#[warn(unexpected_cfgs)]` on by default
  = note: this warning originates in the macro `::pgrx::pgrx_embed` (in Nightly builds, run with -Z macro-backtrace for more info)

warning: unexpected `cfg` condition name: `pgrx_embed`
 --> src/bin/pgrx_embed.rs:1:1
  |
1 | ::pgrx::pgrx_embed!();
  | ^^^^^^^^^^^^^^^^^^^^^
  |
  = help: consider using a Cargo feature instead
  = help: or consider adding in `Cargo.toml` the `check-cfg` lint config for the lint:
           [lints.rust]
           unexpected_cfgs = { level = "warn", check-cfg = ['cfg(pgrx_embed)'] }
  = help: or consider adding `println!("cargo::rustc-check-cfg=cfg(pgrx_embed)");` to the top of the `build.rs`
  = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg/cargo-specifics.html> for more information about checking conditional configuration
  = note: this warning originates in the macro `::pgrx::pgrx_embed` (in Nightly builds, run with -Z macro-backtrace for more info)

warning: `tester` (bin "pgrx_embed_tester") generated 2 warnings
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.35s
     Writing SQL entities to /Users/ccleve/.pgrx/13.18/pgrx-install/share/postgresql/extension/tester--0.0.0.sql
    Finished installing tester
    Starting Postgres v13 on port 28813
     Creating database tester
psql (13.18)
Type "help" for help.

tester=# 

I took the compiler's suggestion to add the println!() line to build.rs and the problem went away.

I'm wondering if Rust changed something.