Reject stdin

crates/uv-cli/src/lib.rs

@@ -1836,8 +1836,6 @@ pub struct RunArgs {
     /// Run with all packages listed in the given `requirements.txt` files.
     ///
     /// Using `pyproject.toml`, `setup.py`, or `setup.cfg` files is not allowed.
-    ///
-    /// If `-` is provided, then requirements will be read from stdin.
     #[arg(long, value_parser = parse_maybe_file_path)]
     pub with_requirements: Vec<Maybe<PathBuf>>,
 

crates/uv/src/commands/project/run.rs

@@ -1,7 +1,7 @@
 use std::borrow::Cow;
 use std::ffi::OsString;
 use std::fmt::Write;
-use std::path::PathBuf;
+use std::path::{Path, PathBuf};
 
 use anyhow::{bail, Context, Result};
 use itertools::Itertools;
@@ -72,6 +72,9 @@ pub(crate) async fn run(
             RequirementsSource::SetupCfg(_) => {
                 bail!("Adding requirements from a `setup.cfg` is not supported in `uv run`");
             }
+            RequirementsSource::RequirementsTxt(path) => if path == Path::new("-") {
+                bail!("Reading requirements from stdin is not supported in `uv run`");
+            }
             _ => {}
         }
     }

crates/uv/tests/run.rs

@@ -700,5 +700,21 @@ fn run_requirements_txt() -> Result<()> {
      + sniffio==1.3.1
     "###);
 
+    // But reject `-` as a requirements file.
+    uv_snapshot!(context.filters(), context.run()
+        .arg("--with-requirements")
+        .arg("-")
+        .arg("--with")
+        .arg("iniconfig")
+        .arg("main.py"), @r###"
+    success: false
+    exit_code: 2
+    ----- stdout -----
+
+    ----- stderr -----
+    warning: `uv run` is experimental and may change without warning
+    error: Reading requirements from stdin is not supported in `uv run`
+    "###);
+
     Ok(())
 }