df: df missing 2>/dev/full does not abort

[tuananh]

Fixes: #10629

[tuananh]

fail in tail

2026-02-03T14:40:07.4337130Z failures:
2026-02-03T14:40:07.4437630Z 
2026-02-03T14:40:07.4538460Z ---- test_tail::test_follow_name_truncate2 stdout ----
2026-02-03T14:40:07.4640090Z bin: "/Users/runner/work/coreutils/coreutils/target/x86_64-apple-darwin/debug/coreutils"
2026-02-03T14:40:07.4720790Z touch: /var/folders/yz/zr09txvs5dn18vt4cn21kzl40000gn/T/.tmpbe8wub/file
2026-02-03T14:40:07.4721760Z run: /Users/runner/work/coreutils/coreutils/target/x86_64-apple-darwin/debug/coreutils tail --follow=name file
2026-02-03T14:40:07.4722430Z write(append): /var/folders/yz/zr09txvs5dn18vt4cn21kzl40000gn/T/.tmpbe8wub/file
2026-02-03T14:40:07.4723160Z write(append): /var/folders/yz/zr09txvs5dn18vt4cn21kzl40000gn/T/.tmpbe8wub/file
2026-02-03T14:40:07.4723780Z write(append): /var/folders/yz/zr09txvs5dn18vt4cn21kzl40000gn/T/.tmpbe8wub/file
2026-02-03T14:40:07.4724330Z write(truncate): /var/folders/yz/zr09txvs5dn18vt4cn21kzl40000gn/T/.tmpbe8wub/file
2026-02-03T14:40:07.4724780Z 
2026-02-03T14:40:07.4725460Z thread 'test_tail::test_follow_name_truncate2' panicked at tests/by-util/test_tail.rs:2077:10:
2026-02-03T14:40:07.4725970Z assertion failed: `(left == right)`
2026-02-03T14:40:07.4726250Z 
2026-02-03T14:40:07.4726700Z �[1mDiff�[0m �[31m< left�[0m / �[32mright >�[0m :
2026-02-03T14:40:07.4727040Z  x
2026-02-03T14:40:07.4727300Z  x
2026-02-03T14:40:07.4727550Z  x
2026-02-03T14:40:07.4727830Z �[32m>x�[0m
2026-02-03T14:40:07.4728090Z  
2026-02-03T14:40:07.4728310Z 
2026-02-03T14:40:07.4728460Z 
2026-02-03T14:40:07.4728660Z stack backtrace:
2026-02-03T14:40:07.4729280Z    0: rust_begin_unwind
2026-02-03T14:40:07.4729990Z              at /rustc/4d91de4e48198da2e33413efdcd9cd2cc0c46688/library/std/src/panicking.rs:692:5
2026-02-03T14:40:07.4730490Z    1: core::panicking::panic_fmt
2026-02-03T14:40:07.4730980Z              at /rustc/4d91de4e48198da2e33413efdcd9cd2cc0c46688/library/core/src/panicking.rs:75:14
2026-02-03T14:40:07.4731480Z    2: uutests::util::CmdResult::stdout_is
2026-02-03T14:40:07.4731870Z              at ./tests/uutests/src/lib/util.rs:530:9
2026-02-03T14:40:07.4732260Z    3: tests::test_tail::test_follow_name_truncate2
2026-02-03T14:40:07.4732650Z              at ./tests/by-util/test_tail.rs:2073:5
2026-02-03T14:40:07.4733300Z    4: tests::test_tail::test_follow_name_truncate2::{{closure}}
2026-02-03T14:40:07.4733740Z              at ./tests/by-util/test_tail.rs:2039:32
2026-02-03T14:40:07.4734190Z    5: core::ops::function::FnOnce::call_once
2026-02-03T14:40:07.4734980Z              at /rustc/4d91de4e48198da2e33413efdcd9cd2cc0c46688/library/core/src/ops/function.rs:250:5
2026-02-03T14:40:07.4735500Z    6: core::ops::function::FnOnce::call_once
2026-02-03T14:40:07.4735990Z              at /rustc/4d91de4e48198da2e33413efdcd9cd2cc0c46688/library/core/src/ops/function.rs:250:5
2026-02-03T14:40:07.4736600Z note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
2026-02-03T14:40:07.4737010Z 
2026-02-03T14:40:07.4737170Z 
2026-02-03T14:40:07.4737370Z failures:
2026-02-03T14:40:07.4737740Z     test_tail::test_follow_name_truncate2
2026-02-03T14:40:07.4738030Z 
2026-02-03T14:40:07.4738490Z test result: FAILED. 4332 passed; 1 failed; 77 ignored; 0 measured; 0 filtered out; finished in 295.35s
2026-02-03T14:40:07.4739140Z 

[AldanTanneo]

There are lots of issues like this one; maybe modifying the show! and related macros instead of replacing each occurrence with let _ = writeln!(...) would be better?

[oech3]

#10646

[AldanTanneo]

@oech3 this is also why a single issue would have been better, it would address the root cause instead of having a fix for each util. It can always be split into sub issues later if there are different problems to be addressed.

[oech3]

Some maintainer is cautious to apply fix at uucore or macros. So merging such PRs sometimes delays.

[oech3]

I was suprised that this was fixed by macro side now. It is unclear form the source. Strange...