From cef9aacdb421ff675b16488a22955a13f4dbdf8f Mon Sep 17 00:00:00 2001
From: Floze <88098863+floze-the-genius@users.noreply.github.com>
Date: Mon, 10 Aug 2026 23:42:45 +0400
Subject: [PATCH] printf: omit errno from write errors

---
 src/uucore/src/lib/features/format/mod.rs |  7 +++++--
 tests/by-util/test_printf.rs              | 12 ++++++++++++
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/src/uucore/src/lib/features/format/mod.rs b/src/uucore/src/lib/features/format/mod.rs
index 1f1c79de556..73db2b4ba28 100644
--- a/src/uucore/src/lib/features/format/mod.rs
+++ b/src/uucore/src/lib/features/format/mod.rs
@@ -42,7 +42,10 @@ use crate::extendedbigdecimal::ExtendedBigDecimal;
 pub use argument::{FormatArgument, FormatArguments};
 
 use self::{escape::parse_escape_code, num_format::Formatter};
-use crate::{NonUtf8OsStrError, error::UError};
+use crate::{
+    NonUtf8OsStrError,
+    error::{UError, strip_errno},
+};
 pub use spec::Spec;
 use std::{
     error::Error,
@@ -113,7 +116,7 @@ impl Display for FormatError {
             Self::InvalidPrecision(precision) => write!(f, "invalid precision: '{precision}'"),
             // TODO: Error message below needs some work
             Self::WrongSpecType => write!(f, "wrong % directive type was given"),
-            Self::IoError(e) => write!(f, "write error: {e}"),
+            Self::IoError(e) => write!(f, "write error: {}", strip_errno(e)),
             Self::NoMoreArguments => write!(f, "no more arguments"),
             Self::InvalidArgument(_) => write!(f, "invalid argument"),
             Self::MissingHex => write!(f, "missing hexadecimal number in escape"),
diff --git a/tests/by-util/test_printf.rs b/tests/by-util/test_printf.rs
index fda7f7d158e..665eac5acd1 100644
--- a/tests/by-util/test_printf.rs
+++ b/tests/by-util/test_printf.rs
@@ -1507,6 +1507,18 @@ fn test_emoji_formatting() {
         .stdout_only("Status: Success 🚀 🎯 Count: 42\n");
 }
 
+#[cfg(target_os = "linux")]
+#[test]
+fn test_write_error_omits_errno() {
+    let dev_full = std::fs::File::create("/dev/full").expect("failed to open /dev/full");
+
+    new_ucmd!()
+        .arg("\n")
+        .set_stdout(dev_full)
+        .fails_with_code(1)
+        .stderr_only("printf: write error: No space left on device\n");
+}
+
 #[test]
 fn test_large_width_format() {
     // Test that extremely large width specifications fail gracefully with an error