sort: report read failures with context

A read error was reported as the bare io::Error string, e.g.
`sort: Input/output error (os error 5)` for `sort /proc/self/mem`.
That names neither the operation that failed nor anything the user
can act on, and the `(os error 5)` suffix is noise.

Wrap it with a "read failed" context and drop the errno suffix using
the existing strip_errno helper, matching the style of the other
SortError variants:

    sort: read failed: Input/output error

Fixes #13992

Author: arcusbuilds

src/uu/sort/locales/en-US.ftl

@@ -14,6 +14,7 @@ sort-after-help = The key format is FIELD[.CHAR][OPTIONS][,FIELD[.CHAR]][OPTIONS
 sort-open-failed = open failed: {$path}: {$error}
 sort-parse-key-error = failed to parse key {$key}: {$msg}
 sort-cannot-read = cannot read: {$path}: {$error}
+sort-read-failed = read failed: {$error}
 sort-open-tmp-file-failed = failed to open temporary file: {$error}
 sort-compress-prog-execution-failed = could not run compress program '{$prog}': {$error}
 sort-compress-prog-terminated-abnormally = {$prog} terminated abnormally

src/uu/sort/locales/fr-FR.ftl

@@ -14,6 +14,7 @@ sort-after-help = Le format de clé est CHAMP[.CAR][OPTIONS][,CHAMP[.CAR]][OPTIO
 sort-open-failed = échec d'ouverture : {$path} : {$error}
 sort-parse-key-error = échec d'analyse de la clé {$key} : {$msg}
 sort-cannot-read = impossible de lire : {$path} : {$error}
+sort-read-failed = échec de lecture : {$error}
 sort-open-tmp-file-failed = échec d'ouverture du fichier temporaire : {$error}
 sort-compress-prog-execution-failed = impossible d'exécuter le programme de compression '{$prog}' : {$error}
 sort-compress-prog-terminated-abnormally = {$prog} s'est terminé anormalement

src/uu/sort/src/chunks.rs

@@ -17,7 +17,8 @@ use std::{
 
 use memchr::memchr_iter;
 use self_cell::self_cell;
-use uucore::error::{UResult, USimpleError};
+use uucore::error::{UResult, USimpleError, strip_errno};
+use uucore::translate;
 
 use crate::{
     GeneralBigDecimalParseResult, GlobalSettings, Line, SortMode, numeric_str_cmp::NumInfo,
@@ -427,7 +428,12 @@ fn read_to_buffer<T: Read>(
             Err(e) if e.kind() == ErrorKind::Interrupted => {
                 // retry
             }
-            Err(e) => return Err(USimpleError::new(2, e.to_string())),
+            Err(e) => {
+                return Err(USimpleError::new(
+                    2,
+                    translate!("sort-read-failed", "error" => strip_errno(&e)),
+                ));
+            }
         }
     }
 }

tests/by-util/test_sort.rs

@@ -1182,6 +1182,18 @@ fn test_merge_write_error_does_not_panic() {
     }
 }
 
+// A read error must be reported with context and without the raw io::Error suffix.
+// It used to print `sort: Input/output error (os error 5)`.
+#[test]
+#[cfg(target_os = "linux")]
+fn test_read_error_message() {
+    // Reading /proc/self/mem from offset 0 fails with EIO.
+    new_ucmd!()
+        .arg("/proc/self/mem")
+        .fails_with_code(2)
+        .stderr_only("sort: read failed: Input/output error\n");
+}
+
 #[test]
 fn test_merge_unique() {
     new_ucmd!()