Recognize UV_NO_INSTALL_PROJECT, UV_NO_INSTALL_WORKSPACE, UV_NO_INSTALL_LOCAL (#19323)

## Summary

Adds environment variable support for `--no-install-project`,
`--no-install-workspace`, and `--no-install-local` so the flags can be
set when uv is invoked through a wrapper that doesn't expose flag
pass-through (Pulumi's `pulumi install` is the example in the issue).

The new env vars (`UV_NO_INSTALL_PROJECT`, `UV_NO_INSTALL_WORKSPACE`,
`UV_NO_INSTALL_LOCAL`) are wired into both `uv sync` and `uv add`, and
apply alongside the CLI flag. If the corresponding `--only-install-*` is
passed on the CLI, the env var is ignored to keep the existing CLI
conflict semantics intact.

Closes #19315.

## Test Plan

Added integration tests for each of the three flags in
`crates/uv/tests/it/sync.rs`, including a check that
`--only-install-project` overrides `UV_NO_INSTALL_PROJECT=1`. Also
verified manually:

```
$ UV_NO_INSTALL_PROJECT=1 uv sync
Installed 1 package in 4ms
 + packaging==26.2
$ uv sync
Installed 2 packages in 5ms
 + demo==0.1.0 (from file:///tmp/demo)
 + packaging==26.2
```

clippy.toml

@@ -22,11 +22,17 @@ doc-valid-idents = [
   "UV_NO_DEV",
   "UV_NO_EDITABLE",
   "UV_NO_ENV_FILE",
+  "UV_NO_INSTALL_LOCAL",
+  "UV_NO_INSTALL_PROJECT",
+  "UV_NO_INSTALL_WORKSPACE",
   "UV_NO_INSTALLER_METADATA",
   "UV_NO_MANAGED_PYTHON",
   "UV_NO_PROGRESS",
   "UV_NO_SYNC",
   "UV_OFFLINE",
+  "UV_ONLY_INSTALL_LOCAL",
+  "UV_ONLY_INSTALL_PROJECT",
+  "UV_ONLY_INSTALL_WORKSPACE",
   "UV_PREVIEW",
   "UV_SHOW_RESOLUTION",
   "UV_VENV_CLEAR",

crates/uv-cli/src/lib.rs

@@ -3999,7 +3999,7 @@ pub struct SyncArgs {
     #[arg(long, overrides_with = "active", hide = true)]
     pub no_active: bool,
 
-    /// Do not install the current project.
+    /// Do not install the current project [env: UV_NO_INSTALL_PROJECT=]
     ///
     /// By default, the current project is installed into the environment with all of its
     /// dependencies. The `--no-install-project` option allows the project to be excluded, but all
@@ -4016,7 +4016,7 @@ pub struct SyncArgs {
     #[arg(long, conflicts_with = "no_install_project", hide = true)]
     pub only_install_project: bool,
 
-    /// Do not install any workspace members, including the root project.
+    /// Do not install any workspace members, including the root project [env: UV_NO_INSTALL_WORKSPACE=]
     ///
     /// By default, all workspace members and their dependencies are installed into the
     /// environment. The `--no-install-workspace` option allows exclusion of all the workspace
@@ -4033,7 +4033,7 @@ pub struct SyncArgs {
     #[arg(long, conflicts_with = "no_install_workspace", hide = true)]
     pub only_install_workspace: bool,
 
-    /// Do not install local path dependencies
+    /// Do not install local path dependencies [env: UV_NO_INSTALL_LOCAL=]
     ///
     /// Skips the current project, workspace members, and any other local (path or editable)
     /// packages. Only remote/indexed dependencies are installed. Useful in Docker builds to cache
@@ -4501,7 +4501,7 @@ pub struct AddArgs {
     #[arg(long, overrides_with = "workspace")]
     pub no_workspace: bool,
 
-    /// Do not install the current project.
+    /// Do not install the current project [env: UV_NO_INSTALL_PROJECT=]
     ///
     /// By default, the current project is installed into the environment with all of its
     /// dependencies. The `--no-install-project` option allows the project to be excluded, but all of
@@ -4529,7 +4529,7 @@ pub struct AddArgs {
     )]
     pub only_install_project: bool,
 
-    /// Do not install any workspace members, including the current project.
+    /// Do not install any workspace members, including the current project [env: UV_NO_INSTALL_WORKSPACE=]
     ///
     /// By default, all workspace members and their dependencies are installed into the
     /// environment. The `--no-install-workspace` option allows exclusion of all the workspace
@@ -4557,7 +4557,7 @@ pub struct AddArgs {
     )]
     pub only_install_workspace: bool,
 
-    /// Do not install local path dependencies
+    /// Do not install local path dependencies [env: UV_NO_INSTALL_LOCAL=]
     ///
     /// Skips the current project, workspace members, and any other local (path or editable)
     /// packages. Only remote/indexed dependencies are installed. Useful in Docker builds to cache

crates/uv-settings/src/lib.rs

@@ -749,6 +749,12 @@ pub struct EnvironmentOptions {
     pub no_dev: EnvFlag,
     pub show_resolution: EnvFlag,
     pub no_editable: EnvFlag,
+    pub no_install_project: EnvFlag,
+    pub no_install_workspace: EnvFlag,
+    pub no_install_local: EnvFlag,
+    pub only_install_project: EnvFlag,
+    pub only_install_workspace: EnvFlag,
+    pub only_install_local: EnvFlag,
     pub no_env_file: EnvFlag,
     pub no_group: Option<Vec<GroupName>>,
     pub no_binary_package: Option<Vec<PackageName>>,
@@ -859,6 +865,12 @@ impl EnvironmentOptions {
             no_dev: EnvFlag::new(EnvVars::UV_NO_DEV)?,
             show_resolution: EnvFlag::new(EnvVars::UV_SHOW_RESOLUTION)?,
             no_editable: EnvFlag::new(EnvVars::UV_NO_EDITABLE)?,
+            no_install_project: EnvFlag::new(EnvVars::UV_NO_INSTALL_PROJECT)?,
+            no_install_workspace: EnvFlag::new(EnvVars::UV_NO_INSTALL_WORKSPACE)?,
+            no_install_local: EnvFlag::new(EnvVars::UV_NO_INSTALL_LOCAL)?,
+            only_install_project: EnvFlag::new(EnvVars::UV_ONLY_INSTALL_PROJECT)?,
+            only_install_workspace: EnvFlag::new(EnvVars::UV_ONLY_INSTALL_WORKSPACE)?,
+            only_install_local: EnvFlag::new(EnvVars::UV_ONLY_INSTALL_LOCAL)?,
             no_env_file: EnvFlag::new(EnvVars::UV_NO_ENV_FILE)?,
             no_group: parse_name_list_environment_variable(EnvVars::UV_NO_GROUP)?,
             no_binary_package: parse_name_list_environment_variable(EnvVars::UV_NO_BINARY_PACKAGE)?,

crates/uv-static/src/env_vars.rs

@@ -260,6 +260,38 @@ impl EnvVars {
     #[attr_added_in("0.9.9")]
     pub const UV_NO_DEFAULT_GROUPS: &'static str = "UV_NO_DEFAULT_GROUPS";
 
+    /// Equivalent to the `--no-install-project` command-line argument. If set, uv will
+    /// install the project's dependencies but not the project itself.
+    #[attr_added_in("next release")]
+    pub const UV_NO_INSTALL_PROJECT: &'static str = "UV_NO_INSTALL_PROJECT";
+
+    /// Equivalent to the `--no-install-workspace` command-line argument. If set, uv will
+    /// install workspace dependencies but not workspace members (including the current
+    /// project).
+    #[attr_added_in("next release")]
+    pub const UV_NO_INSTALL_WORKSPACE: &'static str = "UV_NO_INSTALL_WORKSPACE";
+
+    /// Equivalent to the `--no-install-local` command-line argument. If set, uv will skip
+    /// the current project, workspace members, and any other local (path or editable)
+    /// packages, installing only remote dependencies.
+    #[attr_added_in("next release")]
+    pub const UV_NO_INSTALL_LOCAL: &'static str = "UV_NO_INSTALL_LOCAL";
+
+    /// Equivalent to the hidden `--only-install-project` command-line argument.
+    #[attr_hidden]
+    #[attr_added_in("next release")]
+    pub const UV_ONLY_INSTALL_PROJECT: &'static str = "UV_ONLY_INSTALL_PROJECT";
+
+    /// Equivalent to the hidden `--only-install-workspace` command-line argument.
+    #[attr_hidden]
+    #[attr_added_in("next release")]
+    pub const UV_ONLY_INSTALL_WORKSPACE: &'static str = "UV_ONLY_INSTALL_WORKSPACE";
+
+    /// Equivalent to the hidden `--only-install-local` command-line argument.
+    #[attr_hidden]
+    #[attr_added_in("next release")]
+    pub const UV_ONLY_INSTALL_LOCAL: &'static str = "UV_ONLY_INSTALL_LOCAL";
+
     /// Equivalent to the `--no-binary` command-line argument. If set, uv will install
     /// all packages from source. The resolver will still use pre-built wheels to
     /// extract package metadata, if available.

crates/uv/src/settings.rs

@@ -1794,6 +1794,46 @@ impl SyncSettings {
             Some(environment.no_editable),
         );
 
+        let (no_install_project, only_install_project) = resolve_flag_pair(
+            no_install_project,
+            only_install_project,
+            "no-install-project",
+            "only-install-project",
+            Some(environment.no_install_project),
+            Some(environment.only_install_project),
+        );
+        let (no_install_workspace, only_install_workspace) = resolve_flag_pair(
+            no_install_workspace,
+            only_install_workspace,
+            "no-install-workspace",
+            "only-install-workspace",
+            Some(environment.no_install_workspace),
+            Some(environment.only_install_workspace),
+        );
+        let (no_install_local, only_install_local) = resolve_flag_pair(
+            no_install_local,
+            only_install_local,
+            "no-install-local",
+            "only-install-local",
+            Some(environment.no_install_local),
+            Some(environment.only_install_local),
+        );
+        check_conflicts(no_install_project, only_install_project);
+        check_conflicts(no_install_workspace, only_install_workspace);
+        check_conflicts(no_install_local, only_install_local);
+        if script.is_some() {
+            let script = Flag::from_cli("script");
+            check_conflicts(no_install_project, script);
+            check_conflicts(no_install_workspace, script);
+            check_conflicts(no_install_local, script);
+        }
+        let no_install_project = no_install_project.is_enabled();
+        let only_install_project = only_install_project.is_enabled();
+        let no_install_workspace = no_install_workspace.is_enabled();
+        let only_install_workspace = only_install_workspace.is_enabled();
+        let no_install_local = no_install_local.is_enabled();
+        let only_install_local = only_install_local.is_enabled();
+
         let malware_settings = MalwareCheckSettings::from(&environment);
 
         Self {
@@ -2092,6 +2132,34 @@ impl AddSettings {
             Some(environment.no_editable),
         );
 
+        let (no_install_project, only_install_project) = resolve_flag_pair(
+            no_install_project,
+            only_install_project,
+            "no-install-project",
+            "only-install-project",
+            Some(environment.no_install_project),
+            Some(environment.only_install_project),
+        );
+        let (no_install_workspace, only_install_workspace) = resolve_flag_pair(
+            no_install_workspace,
+            only_install_workspace,
+            "no-install-workspace",
+            "only-install-workspace",
+            Some(environment.no_install_workspace),
+            Some(environment.only_install_workspace),
+        );
+        let (no_install_local, only_install_local) = resolve_flag_pair(
+            no_install_local,
+            only_install_local,
+            "no-install-local",
+            "only-install-local",
+            Some(environment.no_install_local),
+            Some(environment.only_install_local),
+        );
+        check_conflicts(no_install_project, only_install_project);
+        check_conflicts(no_install_workspace, only_install_workspace);
+        check_conflicts(no_install_local, only_install_local);
+
         let dependency_type = if let Some(extra) = optional {
             DependencyType::Optional(extra)
         } else if let Some(group) = group {
@@ -2169,6 +2237,38 @@ impl AddSettings {
         // Check for conflicts between no_sync and frozen.
         check_conflicts(no_sync, frozen);
 
+        let no_install_package_flag = if no_install_package.is_empty() {
+            Flag::disabled()
+        } else {
+            Flag::from_cli("no-install-package")
+        };
+        let only_install_package_flag = if only_install_package.is_empty() {
+            Flag::disabled()
+        } else {
+            Flag::from_cli("only-install-package")
+        };
+
+        for install_flag in [
+            no_install_project,
+            no_install_workspace,
+            no_install_local,
+            only_install_project,
+            only_install_workspace,
+            only_install_local,
+            no_install_package_flag,
+            only_install_package_flag,
+        ] {
+            check_conflicts(install_flag, frozen);
+            check_conflicts(install_flag, no_sync);
+        }
+
+        let no_install_project = no_install_project.is_enabled();
+        let only_install_project = only_install_project.is_enabled();
+        let no_install_workspace = no_install_workspace.is_enabled();
+        let only_install_workspace = only_install_workspace.is_enabled();
+        let no_install_local = no_install_local.is_enabled();
+        let only_install_local = only_install_local.is_enabled();
+
         let malware_settings = MalwareCheckSettings::from(&environment);
 
         Self {

crates/uv/tests/it/edit.rs

@@ -15491,6 +15491,36 @@ fn add_no_install_project() -> Result<()> {
         );
     });
 
+    uv_snapshot!(context.filters(), context.add().arg("typing-extensions").env(EnvVars::UV_NO_INSTALL_PROJECT, "1"), @"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Resolved 3 packages in [TIME]
+    Prepared 1 package in [TIME]
+    Installed 1 package in [TIME]
+     + typing-extensions==4.10.0
+    ");
+
+    uv_snapshot!(context.filters(), context.add().arg("typing-extensions").arg("--frozen").env(EnvVars::UV_NO_INSTALL_PROJECT, "1"), @"
+    success: false
+    exit_code: 2
+    ----- stdout -----
+
+    ----- stderr -----
+    error: the argument `UV_NO_INSTALL_PROJECT` (environment variable) cannot be used with `--frozen`
+    ");
+
+    uv_snapshot!(context.filters(), context.add().arg("typing-extensions").arg("--frozen").env(EnvVars::UV_ONLY_INSTALL_PROJECT, "1"), @"
+    success: false
+    exit_code: 2
+    ----- stdout -----
+
+    ----- stderr -----
+    error: the argument `UV_ONLY_INSTALL_PROJECT` (environment variable) cannot be used with `--frozen`
+    ");
+
     Ok(())
 }
 

crates/uv/tests/it/sync.rs

@@ -5849,6 +5849,39 @@ fn no_install_project() -> Result<()> {
      + sniffio==1.3.1
     ");
 
+    fs_err::remove_dir_all(&context.venv)?;
+
+    uv_snapshot!(context.filters(), context.sync().env(EnvVars::UV_NO_INSTALL_PROJECT, "1"), @"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Using CPython 3.12.[X] interpreter at: [PYTHON-3.12]
+    Creating virtual environment at: .venv
+    Resolved 4 packages in [TIME]
+    Installed 3 packages in [TIME]
+     + anyio==3.7.0
+     + idna==3.6
+     + sniffio==1.3.1
+    ");
+
+    uv_snapshot!(context.filters(), context.sync().env(EnvVars::UV_ONLY_INSTALL_PROJECT, "1"), @"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Resolved 4 packages in [TIME]
+    Prepared 1 package in [TIME]
+    Uninstalled 3 packages in [TIME]
+    Installed 1 package in [TIME]
+     - anyio==3.7.0
+     - idna==3.6
+     + project==0.1.0 (from file://[TEMP_DIR]/)
+     - sniffio==1.3.1
+    ");
+
     // However, we do require the `pyproject.toml`.
     fs_err::remove_file(pyproject_toml)?;
 
@@ -5941,6 +5974,23 @@ fn no_install_workspace() -> Result<()> {
     // Remove the virtual environment.
     fs_err::remove_dir_all(&context.venv)?;
 
+    uv_snapshot!(context.filters(), context.sync().arg("--frozen").env(EnvVars::UV_NO_INSTALL_WORKSPACE, "1"), @"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Using CPython 3.12.[X] interpreter at: [PYTHON-3.12]
+    Creating virtual environment at: .venv
+    Installed 4 packages in [TIME]
+     + anyio==3.7.0
+     + idna==3.6
+     + iniconfig==2.0.0
+     + sniffio==1.3.1
+    ");
+
+    fs_err::remove_dir_all(&context.venv)?;
+
     // We don't require the `pyproject.toml` for non-root members, if `--frozen` is provided.
     fs_err::remove_file(child.join("pyproject.toml"))?;
 
@@ -6097,6 +6147,56 @@ fn no_install_local() -> Result<()> {
      + sniffio==1.3.1
     ");
 
+    fs_err::remove_dir_all(&context.venv)?;
+
+    uv_snapshot!(context.filters(), context.sync().arg("--frozen").env(EnvVars::UV_NO_INSTALL_LOCAL, "1"), @"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Using CPython 3.12.[X] interpreter at: [PYTHON-3.12]
+    Creating virtual environment at: .venv
+    Installed 3 packages in [TIME]
+     + anyio==3.7.0
+     + idna==3.6
+     + sniffio==1.3.1
+    ");
+
+    Ok(())
+}
+
+/// `UV_NO_INSTALL_PROJECT=1` should conflict with `--script`, just like
+/// `--no-install-project`.
+#[test]
+fn no_install_env_var_conflicts() -> Result<()> {
+    let context = uv_test::test_context!("3.12");
+
+    let script = context.temp_dir.child("script.py");
+    script.write_str(indoc! {r#"
+        # /// script
+        # requires-python = ">=3.12"
+        # ///
+    "#})?;
+
+    uv_snapshot!(context.filters(), context.sync().arg("--script").arg("script.py").env(EnvVars::UV_NO_INSTALL_PROJECT, "1"), @"
+    success: false
+    exit_code: 2
+    ----- stdout -----
+
+    ----- stderr -----
+    error: the argument `UV_NO_INSTALL_PROJECT` (environment variable) cannot be used with `--script`
+    ");
+
+    uv_snapshot!(context.filters(), context.sync().arg("--script").arg("script.py").env(EnvVars::UV_NO_INSTALL_PROJECT, "1").env(EnvVars::UV_ONLY_INSTALL_PROJECT, "1"), @"
+    success: false
+    exit_code: 2
+    ----- stdout -----
+
+    ----- stderr -----
+    error: the argument `UV_NO_INSTALL_PROJECT` (environment variable) cannot be used with `UV_ONLY_INSTALL_PROJECT` (environment variable)
+    ");
+
     Ok(())
 }