Add `UV_HIDE_BUILD_OUTPUT` to omit build logs (#16885)

## Summary

Closes #16804.

Cargo.lock

@@ -5994,6 +5994,7 @@ dependencies = [
  "uv-distribution-filename",
  "uv-distribution-types",
  "uv-extract",
+ "uv-flags",
  "uv-fs",
  "uv-git",
  "uv-git-types",

crates/uv-distribution/Cargo.toml

@@ -24,6 +24,7 @@ uv-configuration = { workspace = true }
 uv-distribution-filename = { workspace = true }
 uv-distribution-types = { workspace = true }
 uv-extract = { workspace = true }
+uv-flags = { workspace = true }
 uv-fs = { workspace = true, features = ["tokio"] }
 uv-git = { workspace = true }
 uv-git-types = { workspace = true }

crates/uv-distribution/src/source/mod.rs

@@ -2503,7 +2503,11 @@ impl<'a, T: BuildContext> SourceDistributionBuilder<'a, T> {
                         } else {
                             BuildKind::Wheel
                         },
-                        BuildOutput::Debug,
+                        if uv_flags::contains(uv_flags::EnvironmentFlags::HIDE_BUILD_OUTPUT) {
+                            BuildOutput::Quiet
+                        } else {
+                            BuildOutput::Debug
+                        },
                         self.build_stack.cloned().unwrap_or_default(),
                     )
                     .await
@@ -2604,7 +2608,11 @@ impl<'a, T: BuildContext> SourceDistributionBuilder<'a, T> {
                 source.as_dist(),
                 source_strategy,
                 build_kind,
-                BuildOutput::Debug,
+                if uv_flags::contains(uv_flags::EnvironmentFlags::HIDE_BUILD_OUTPUT) {
+                    BuildOutput::Quiet
+                } else {
+                    BuildOutput::Debug
+                },
                 self.build_stack.cloned().unwrap_or_default(),
             )
             .await

crates/uv-flags/src/lib.rs

@@ -6,6 +6,7 @@ bitflags::bitflags! {
     #[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
     pub struct EnvironmentFlags: u32 {
         const SKIP_WHEEL_FILENAME_CHECK = 1 << 0;
+        const HIDE_BUILD_OUTPUT = 1 << 1;
     }
 }
 

crates/uv-settings/src/lib.rs

@@ -585,6 +585,7 @@ pub struct Concurrency {
 #[derive(Debug, Clone)]
 pub struct EnvironmentOptions {
     pub skip_wheel_filename_check: Option<bool>,
+    pub hide_build_output: Option<bool>,
     pub python_install_bin: Option<bool>,
     pub python_install_registry: Option<bool>,
     pub install_mirrors: PythonInstallMirrors,
@@ -613,6 +614,7 @@ impl EnvironmentOptions {
             skip_wheel_filename_check: parse_boolish_environment_variable(
                 EnvVars::UV_SKIP_WHEEL_FILENAME_CHECK,
             )?,
+            hide_build_output: parse_boolish_environment_variable(EnvVars::UV_HIDE_BUILD_OUTPUT)?,
             python_install_bin: parse_boolish_environment_variable(EnvVars::UV_PYTHON_INSTALL_BIN)?,
             python_install_registry: parse_boolish_environment_variable(
                 EnvVars::UV_PYTHON_INSTALL_REGISTRY,
@@ -775,6 +777,9 @@ impl From<&EnvironmentOptions> for EnvironmentFlags {
         if options.skip_wheel_filename_check == Some(true) {
             flags.insert(Self::SKIP_WHEEL_FILENAME_CHECK);
         }
+        if options.hide_build_output == Some(true) {
+            flags.insert(Self::HIDE_BUILD_OUTPUT);
+        }
         flags
     }
 }

crates/uv-static/src/env_vars.rs

@@ -1236,4 +1236,9 @@ impl EnvVars {
     /// around invalid artifacts in rare cases.
     #[attr_added_in("0.8.23")]
     pub const UV_SKIP_WHEEL_FILENAME_CHECK: &'static str = "UV_SKIP_WHEEL_FILENAME_CHECK";
+
+    /// Suppress output from the build backend when building source distributions, even in the event
+    /// of build failures.
+    #[attr_added_in("0.9.14")]
+    pub const UV_HIDE_BUILD_OUTPUT: &'static str = "UV_HIDE_BUILD_OUTPUT";
 }

crates/uv/src/commands/build_frontend.rs

@@ -663,7 +663,7 @@ async fn build_package(
 
     let build_output = match printer {
         Printer::Default | Printer::NoProgress | Printer::Verbose => {
-            if build_logs {
+            if build_logs && !uv_flags::contains(uv_flags::EnvironmentFlags::HIDE_BUILD_OUTPUT) {
                 BuildOutput::Stderr
             } else {
                 BuildOutput::Quiet

crates/uv/tests/it/build.rs

@@ -1180,6 +1180,102 @@ fn build_no_build_logs() -> Result<()> {
     Ok(())
 }
 
+/// Test that `UV_HIDE_BUILD_OUTPUT` suppresses build output.
+#[test]
+fn build_hide_build_output_env_var() -> Result<()> {
+    let context = TestContext::new("3.12");
+
+    let project = context.temp_dir.child("project");
+
+    let pyproject_toml = project.child("pyproject.toml");
+    pyproject_toml.write_str(
+        r#"
+        [project]
+        name = "project"
+        version = "0.1.0"
+        requires-python = ">=3.12"
+        dependencies = ["anyio==3.7.0"]
+
+        [build-system]
+        requires = ["hatchling"]
+        build-backend = "hatchling.build"
+        "#,
+    )?;
+
+    project
+        .child("src")
+        .child("project")
+        .child("__init__.py")
+        .touch()?;
+    project.child("README").touch()?;
+
+    uv_snapshot!(&context.filters(), context.build().arg("project").env(EnvVars::UV_HIDE_BUILD_OUTPUT, "1"), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Building source distribution...
+    Building wheel from source distribution...
+    Successfully built project/dist/project-0.1.0.tar.gz
+    Successfully built project/dist/project-0.1.0-py3-none-any.whl
+    "###);
+
+    Ok(())
+}
+
+/// Test that `UV_HIDE_BUILD_OUTPUT` hides build output even on failure.
+#[test]
+fn build_hide_build_output_on_failure() -> Result<()> {
+    let context = TestContext::new("3.12");
+    let filters = context
+        .filters()
+        .into_iter()
+        .chain([(r"\\\.", "")])
+        .collect::<Vec<_>>();
+
+    let project = context.temp_dir.child("project");
+
+    let pyproject_toml = project.child("pyproject.toml");
+    pyproject_toml.write_str(
+        r#"
+        [project]
+        name = "project"
+        version = "0.1.0"
+        requires-python = ">=3.12"
+
+        [build-system]
+        requires = ["setuptools"]
+        build-backend = "setuptools.build_meta"
+        "#,
+    )?;
+
+    // Create a `setup.py` that prints an environment variable before failing.
+    project.child("setup.py").write_str(indoc! {r#"
+        import os
+        import sys
+        print("FOO=" + os.environ.get("FOO", "not-set"), file=sys.stderr)
+        sys.stderr.flush()
+        raise Exception("Build failed intentionally!")
+        "#})?;
+
+    // With `UV_HIDE_BUILD_OUTPUT`, the output is hidden even on failure.
+    uv_snapshot!(&filters, context.build().arg("project").env(EnvVars::UV_HIDE_BUILD_OUTPUT, "1").env("FOO", "bar"), @r###"
+    success: false
+    exit_code: 2
+    ----- stdout -----
+
+    ----- stderr -----
+    Building source distribution...
+      × Failed to build `[TEMP_DIR]/project`
+      ├─▶ The build backend returned an error
+      ╰─▶ Call to `setuptools.build_meta.build_sdist` failed (exit status: 1)
+          hint: This usually indicates a problem with the package or the build environment.
+    "###);
+
+    Ok(())
+}
+
 #[test]
 fn build_tool_uv_sources() -> Result<()> {
     let context = TestContext::new("3.12");

docs/reference/environment.md

@@ -150,6 +150,12 @@ Equivalent to the `--token` argument for self update. A GitHub token for authent
 
 Enables fetching files stored in Git LFS when installing a package from a Git repository.
 
+### `UV_HIDE_BUILD_OUTPUT`
+<small class="added-in">added in `0.9.14`</small>
+
+Suppress output from the build backend when building source distributions, even in the event
+of build failures.
+
 ### `UV_HTTP_RETRIES`
 <small class="added-in">added in `0.7.21`</small>