`rustdoc` only recognizes `--remap-path-prefix` starting with Rust 1.81.0, which is later than on minimum, so we cannot pass it unconditionally. Otherwise, we get: error: Unrecognized option: 'remap-path-prefix' Note that `rustc` (the compiler) does recognize the flag since a long time ago (1.26.0). Moreover, `rustdoc` since Rust 1.82.0 ICEs in out-of-tree builds when using `--remap-path-prefix`. The issue has been reduced and reported upstream [1]. Thus workaround both issues by simply skipping the flag when generating the docs -- it is not critical there anyway. The ICE does not reproduce under `--test`, but we still need to skip the flag as well for `RUSTDOC TK` since it is not recognized. Fixes: 6b5747d07138 ("kbuild, rust: use -fremap-path-prefix to make paths relative") Link: https://github.com/rust-lang/rust/issues/138520 [1] Signed-off-by: Miguel Ojeda <ojeda@xxxxxxxxxx> --- v2: - Skip the flag also in `RUSTDOC TK`. The ICE does not apply there, but we still need to skip the flag. rust/Makefile | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/rust/Makefile b/rust/Makefile index ea3849eb78f6..089473a89d46 100644 --- a/rust/Makefile +++ b/rust/Makefile @@ -57,10 +57,14 @@ endif core-cfgs = \ --cfg no_fp_fmt_parse +# `rustc` recognizes `--remap-path-prefix` since 1.26.0, but `rustdoc` only +# since Rust 1.81.0. Moreover, `rustdoc` ICEs on out-of-tree builds since Rust +# 1.82.0 (https://github.com/rust-lang/rust/issues/138520). Thus workaround both +# issues skipping the flag. The former also applies to `RUSTDOC TK`. quiet_cmd_rustdoc = RUSTDOC $(if $(rustdoc_host),H, ) $< cmd_rustdoc = \ OBJTREE=$(abspath $(objtree)) \ - $(RUSTDOC) $(filter-out $(skip_flags),$(if $(rustdoc_host),$(rust_common_flags),$(rust_flags))) \ + $(RUSTDOC) $(filter-out $(skip_flags) --remap-path-prefix=%,$(if $(rustdoc_host),$(rust_common_flags),$(rust_flags))) \ $(rustc_target_flags) -L$(objtree)/$(obj) \ -Zunstable-options --generate-link-to-definition \ --output $(rustdoc_output) \ @@ -171,7 +175,7 @@ quiet_cmd_rustdoc_test_kernel = RUSTDOC TK $< rm -rf $(objtree)/$(obj)/test/doctests/kernel; \ mkdir -p $(objtree)/$(obj)/test/doctests/kernel; \ OBJTREE=$(abspath $(objtree)) \ - $(RUSTDOC) --test $(rust_flags) \ + $(RUSTDOC) --test $(filter-out --remap-path-prefix=%,$(rust_flags)) \ -L$(objtree)/$(obj) --extern ffi --extern kernel \ --extern build_error --extern macros \ --extern bindings --extern uapi \ base-commit: bc5431693696b3f928b0b7acf8d7a120127db7a4 -- 2.49.0