fix: don't modify dotfiles when install_dir in PATH

This is a proof-of-concept for astral-sh/uv#5576 and #830: When the install dir is already in PATH, don't modify the user's dotfile.

For my use case, i set `export PATH="$HOME/.cargo/bin/:$PATH"` manually and don't want to source arbitrary other files; I've had bad experiences with tools that would make intrusive changes to my shell by souring their slow script on every bash startup, and a single file configuration is much easier to debug.

Caveat: I have no idea how portable this code is.

cargo-dist/templates/installer/installer.sh.j2

@@ -479,6 +479,12 @@ install() {
 
     say "{{ install_success_msg }}"
 
+    # Avoid modifying the users PATH if they are managing their PATH manually
+    case :$PATH:
+      in *:$_install_dir:*) NO_MODIFY_PATH=1 ;;
+         *) ;;
+    esac
+
     if [ "0" = "$NO_MODIFY_PATH" ]; then
         add_install_dir_to_ci_path "$_install_dir"
         add_install_dir_to_path "$_install_dir_expr" "$_env_script_path" "$_env_script_path_expr" ".profile" "sh"

cargo-dist/tests/snapshots/akaikatana_basic.snap

@@ -1,6 +1,5 @@
 ---
 source: cargo-dist/tests/gallery/dist/snapshot.rs
-assertion_line: 92
 expression: self.payload
 ---
 ================ akaikatana-repack-installer.sh ================
@@ -486,6 +485,12 @@ install() {
 
     say "everything's installed!"
 
+    # Avoid modifying the users PATH if they are managing their PATH manually
+    case :$PATH:
+      in *:$_install_dir:*) NO_MODIFY_PATH=1 ;;
+         *) ;;
+    esac
+
     if [ "0" = "$NO_MODIFY_PATH" ]; then
         add_install_dir_to_ci_path "$_install_dir"
         add_install_dir_to_path "$_install_dir_expr" "$_env_script_path" "$_env_script_path_expr" ".profile" "sh"

cargo-dist/tests/snapshots/akaikatana_musl.snap

@@ -1,6 +1,5 @@
 ---
 source: cargo-dist/tests/gallery/dist/snapshot.rs
-assertion_line: 92
 expression: self.payload
 ---
 ================ akaikatana-repack-installer.sh ================
@@ -508,6 +507,12 @@ install() {
 
     say "everything's installed!"
 
+    # Avoid modifying the users PATH if they are managing their PATH manually
+    case :$PATH:
+      in *:$_install_dir:*) NO_MODIFY_PATH=1 ;;
+         *) ;;
+    esac
+
     if [ "0" = "$NO_MODIFY_PATH" ]; then
         add_install_dir_to_ci_path "$_install_dir"
         add_install_dir_to_path "$_install_dir_expr" "$_env_script_path" "$_env_script_path_expr" ".profile" "sh"

cargo-dist/tests/snapshots/akaikatana_one_alias_among_many_binaries.snap

@@ -1,6 +1,5 @@
 ---
 source: cargo-dist/tests/gallery/dist/snapshot.rs
-assertion_line: 92
 expression: self.payload
 ---
 ================ akaikatana-repack-installer.sh ================
@@ -498,6 +497,12 @@ install() {
 
     say "everything's installed!"
 
+    # Avoid modifying the users PATH if they are managing their PATH manually
+    case :$PATH:
+      in *:$_install_dir:*) NO_MODIFY_PATH=1 ;;
+         *) ;;
+    esac
+
     if [ "0" = "$NO_MODIFY_PATH" ]; then
         add_install_dir_to_ci_path "$_install_dir"
         add_install_dir_to_path "$_install_dir_expr" "$_env_script_path" "$_env_script_path_expr" ".profile" "sh"

cargo-dist/tests/snapshots/akaikatana_two_bin_aliases.snap

@@ -1,6 +1,5 @@
 ---
 source: cargo-dist/tests/gallery/dist/snapshot.rs
-assertion_line: 92
 expression: self.payload
 ---
 ================ akaikatana-repack-installer.sh ================
@@ -510,6 +509,12 @@ install() {
 
     say "everything's installed!"
 
+    # Avoid modifying the users PATH if they are managing their PATH manually
+    case :$PATH:
+      in *:$_install_dir:*) NO_MODIFY_PATH=1 ;;
+         *) ;;
+    esac
+
     if [ "0" = "$NO_MODIFY_PATH" ]; then
         add_install_dir_to_ci_path "$_install_dir"
         add_install_dir_to_path "$_install_dir_expr" "$_env_script_path" "$_env_script_path_expr" ".profile" "sh"

cargo-dist/tests/snapshots/akaikatana_updaters.snap

@@ -1,6 +1,5 @@
 ---
 source: cargo-dist/tests/gallery/dist/snapshot.rs
-assertion_line: 92
 expression: self.payload
 ---
 ================ akaikatana-repack-installer.sh ================
@@ -486,6 +485,12 @@ install() {
 
     say "everything's installed!"
 
+    # Avoid modifying the users PATH if they are managing their PATH manually
+    case :$PATH:
+      in *:$_install_dir:*) NO_MODIFY_PATH=1 ;;
+         *) ;;
+    esac
+
     if [ "0" = "$NO_MODIFY_PATH" ]; then
         add_install_dir_to_ci_path "$_install_dir"
         add_install_dir_to_path "$_install_dir_expr" "$_env_script_path" "$_env_script_path_expr" ".profile" "sh"

cargo-dist/tests/snapshots/axolotlsay_abyss.snap

@@ -485,6 +485,12 @@ install() {
 
     say "everything's installed!"
 
+    # Avoid modifying the users PATH if they are managing their PATH manually
+    case :$PATH:
+      in *:$_install_dir:*) NO_MODIFY_PATH=1 ;;
+         *) ;;
+    esac
+
     if [ "0" = "$NO_MODIFY_PATH" ]; then
         add_install_dir_to_ci_path "$_install_dir"
         add_install_dir_to_path "$_install_dir_expr" "$_env_script_path" "$_env_script_path_expr" ".profile" "sh"

cargo-dist/tests/snapshots/axolotlsay_abyss_only.snap

@@ -485,6 +485,12 @@ install() {
 
     say "everything's installed!"
 
+    # Avoid modifying the users PATH if they are managing their PATH manually
+    case :$PATH:
+      in *:$_install_dir:*) NO_MODIFY_PATH=1 ;;
+         *) ;;
+    esac
+
     if [ "0" = "$NO_MODIFY_PATH" ]; then
         add_install_dir_to_ci_path "$_install_dir"
         add_install_dir_to_path "$_install_dir_expr" "$_env_script_path" "$_env_script_path_expr" ".profile" "sh"

cargo-dist/tests/snapshots/axolotlsay_alias.snap

@@ -497,6 +497,12 @@ install() {
 
     say "everything's installed!"
 
+    # Avoid modifying the users PATH if they are managing their PATH manually
+    case :$PATH:
+      in *:$_install_dir:*) NO_MODIFY_PATH=1 ;;
+         *) ;;
+    esac
+
     if [ "0" = "$NO_MODIFY_PATH" ]; then
         add_install_dir_to_ci_path "$_install_dir"
         add_install_dir_to_path "$_install_dir_expr" "$_env_script_path" "$_env_script_path_expr" ".profile" "sh"

cargo-dist/tests/snapshots/axolotlsay_alias_ignores_missing_bins.snap

@@ -497,6 +497,12 @@ install() {
 
     say "everything's installed!"
 
+    # Avoid modifying the users PATH if they are managing their PATH manually
+    case :$PATH:
+      in *:$_install_dir:*) NO_MODIFY_PATH=1 ;;
+         *) ;;
+    esac
+
     if [ "0" = "$NO_MODIFY_PATH" ]; then
         add_install_dir_to_ci_path "$_install_dir"
         add_install_dir_to_path "$_install_dir_expr" "$_env_script_path" "$_env_script_path_expr" ".profile" "sh"

cargo-dist/tests/snapshots/axolotlsay_basic.snap

@@ -485,6 +485,12 @@ install() {
 
     say ">o_o< everything's installed!"
 
+    # Avoid modifying the users PATH if they are managing their PATH manually
+    case :$PATH:
+      in *:$_install_dir:*) NO_MODIFY_PATH=1 ;;
+         *) ;;
+    esac
+
     if [ "0" = "$NO_MODIFY_PATH" ]; then
         add_install_dir_to_ci_path "$_install_dir"
         add_install_dir_to_path "$_install_dir_expr" "$_env_script_path" "$_env_script_path_expr" ".profile" "sh"

cargo-dist/tests/snapshots/axolotlsay_basic_lies.snap

@@ -485,6 +485,12 @@ install() {
 
     say "everything's installed!"
 
+    # Avoid modifying the users PATH if they are managing their PATH manually
+    case :$PATH:
+      in *:$_install_dir:*) NO_MODIFY_PATH=1 ;;
+         *) ;;
+    esac
+
     if [ "0" = "$NO_MODIFY_PATH" ]; then
         add_install_dir_to_ci_path "$_install_dir"
         add_install_dir_to_path "$_install_dir_expr" "$_env_script_path" "$_env_script_path_expr" ".profile" "sh"

cargo-dist/tests/snapshots/axolotlsay_build_setup_steps.snap

@@ -485,6 +485,12 @@ install() {
 
     say ">o_o< everything's installed!"
 
+    # Avoid modifying the users PATH if they are managing their PATH manually
+    case :$PATH:
+      in *:$_install_dir:*) NO_MODIFY_PATH=1 ;;
+         *) ;;
+    esac
+
     if [ "0" = "$NO_MODIFY_PATH" ]; then
         add_install_dir_to_ci_path "$_install_dir"
         add_install_dir_to_path "$_install_dir_expr" "$_env_script_path" "$_env_script_path_expr" ".profile" "sh"

cargo-dist/tests/snapshots/axolotlsay_checksum_blake2b.snap

@@ -1,6 +1,5 @@
 ---
 source: cargo-dist/tests/gallery/dist/snapshot.rs
-assertion_line: 92
 expression: self.payload
 ---
 ================ axolotlsay-installer.sh ================
@@ -486,6 +485,12 @@ install() {
 
     say "everything's installed!"
 
+    # Avoid modifying the users PATH if they are managing their PATH manually
+    case :$PATH:
+      in *:$_install_dir:*) NO_MODIFY_PATH=1 ;;
+         *) ;;
+    esac
+
     if [ "0" = "$NO_MODIFY_PATH" ]; then
         add_install_dir_to_ci_path "$_install_dir"
         add_install_dir_to_path "$_install_dir_expr" "$_env_script_path" "$_env_script_path_expr" ".profile" "sh"

cargo-dist/tests/snapshots/axolotlsay_checksum_blake2s.snap

@@ -1,6 +1,5 @@
 ---
 source: cargo-dist/tests/gallery/dist/snapshot.rs
-assertion_line: 92
 expression: self.payload
 ---
 ================ axolotlsay-installer.sh ================
@@ -486,6 +485,12 @@ install() {
 
     say "everything's installed!"
 
+    # Avoid modifying the users PATH if they are managing their PATH manually
+    case :$PATH:
+      in *:$_install_dir:*) NO_MODIFY_PATH=1 ;;
+         *) ;;
+    esac
+
     if [ "0" = "$NO_MODIFY_PATH" ]; then
         add_install_dir_to_ci_path "$_install_dir"
         add_install_dir_to_path "$_install_dir_expr" "$_env_script_path" "$_env_script_path_expr" ".profile" "sh"

cargo-dist/tests/snapshots/axolotlsay_checksum_sha3_256.snap

@@ -1,6 +1,5 @@
 ---
 source: cargo-dist/tests/gallery/dist/snapshot.rs
-assertion_line: 92
 expression: self.payload
 ---
 ================ axolotlsay-installer.sh ================
@@ -486,6 +485,12 @@ install() {
 
     say "everything's installed!"
 
+    # Avoid modifying the users PATH if they are managing their PATH manually
+    case :$PATH:
+      in *:$_install_dir:*) NO_MODIFY_PATH=1 ;;
+         *) ;;
+    esac
+
     if [ "0" = "$NO_MODIFY_PATH" ]; then
         add_install_dir_to_ci_path "$_install_dir"
         add_install_dir_to_path "$_install_dir_expr" "$_env_script_path" "$_env_script_path_expr" ".profile" "sh"

cargo-dist/tests/snapshots/axolotlsay_checksum_sha3_512.snap

@@ -1,6 +1,5 @@
 ---
 source: cargo-dist/tests/gallery/dist/snapshot.rs
-assertion_line: 92
 expression: self.payload
 ---
 ================ axolotlsay-installer.sh ================
@@ -486,6 +485,12 @@ install() {
 
     say "everything's installed!"
 
+    # Avoid modifying the users PATH if they are managing their PATH manually
+    case :$PATH:
+      in *:$_install_dir:*) NO_MODIFY_PATH=1 ;;
+         *) ;;
+    esac
+
     if [ "0" = "$NO_MODIFY_PATH" ]; then
         add_install_dir_to_ci_path "$_install_dir"
         add_install_dir_to_path "$_install_dir_expr" "$_env_script_path" "$_env_script_path_expr" ".profile" "sh"

cargo-dist/tests/snapshots/axolotlsay_disable_source_tarball.snap

@@ -485,6 +485,12 @@ install() {
 
     say "everything's installed!"
 
+    # Avoid modifying the users PATH if they are managing their PATH manually
+    case :$PATH:
+      in *:$_install_dir:*) NO_MODIFY_PATH=1 ;;
+         *) ;;
+    esac
+
     if [ "0" = "$NO_MODIFY_PATH" ]; then
         add_install_dir_to_ci_path "$_install_dir"
         add_install_dir_to_path "$_install_dir_expr" "$_env_script_path" "$_env_script_path_expr" ".profile" "sh"

cargo-dist/tests/snapshots/axolotlsay_edit_existing.snap

@@ -485,6 +485,12 @@ install() {
 
     say "everything's installed!"
 
+    # Avoid modifying the users PATH if they are managing their PATH manually
+    case :$PATH:
+      in *:$_install_dir:*) NO_MODIFY_PATH=1 ;;
+         *) ;;
+    esac
+
     if [ "0" = "$NO_MODIFY_PATH" ]; then
         add_install_dir_to_ci_path "$_install_dir"
         add_install_dir_to_path "$_install_dir_expr" "$_env_script_path" "$_env_script_path_expr" ".profile" "sh"

cargo-dist/tests/snapshots/axolotlsay_generic_workspace_basic.snap

@@ -1,6 +1,5 @@
 ---
 source: cargo-dist/tests/gallery/dist/snapshot.rs
-assertion_line: 106
 expression: self.payload
 ---
 ================ axolotlsay-js-installer.sh ================
@@ -486,6 +485,12 @@ install() {
 
     say ">o_o< everything's installed!"
 
+    # Avoid modifying the users PATH if they are managing their PATH manually
+    case :$PATH:
+      in *:$_install_dir:*) NO_MODIFY_PATH=1 ;;
+         *) ;;
+    esac
+
     if [ "0" = "$NO_MODIFY_PATH" ]; then
         add_install_dir_to_ci_path "$_install_dir"
         add_install_dir_to_path "$_install_dir_expr" "$_env_script_path" "$_env_script_path_expr" ".profile" "sh"
@@ -2045,6 +2050,12 @@ install() {
 
     say ">o_o< everything's installed!"
 
+    # Avoid modifying the users PATH if they are managing their PATH manually
+    case :$PATH:
+      in *:$_install_dir:*) NO_MODIFY_PATH=1 ;;
+         *) ;;
+    esac
+
     if [ "0" = "$NO_MODIFY_PATH" ]; then
         add_install_dir_to_ci_path "$_install_dir"
         add_install_dir_to_path "$_install_dir_expr" "$_env_script_path" "$_env_script_path_expr" ".profile" "sh"

cargo-dist/tests/snapshots/axolotlsay_homebrew_packages.snap

@@ -485,6 +485,12 @@ install() {
 
     say "everything's installed!"
 
+    # Avoid modifying the users PATH if they are managing their PATH manually
+    case :$PATH:
+      in *:$_install_dir:*) NO_MODIFY_PATH=1 ;;
+         *) ;;
+    esac
+
     if [ "0" = "$NO_MODIFY_PATH" ]; then
         add_install_dir_to_ci_path "$_install_dir"
         add_install_dir_to_path "$_install_dir_expr" "$_env_script_path" "$_env_script_path_expr" ".profile" "sh"

cargo-dist/tests/snapshots/axolotlsay_musl.snap

@@ -507,6 +507,12 @@ install() {
 
     say "everything's installed!"
 
+    # Avoid modifying the users PATH if they are managing their PATH manually
+    case :$PATH:
+      in *:$_install_dir:*) NO_MODIFY_PATH=1 ;;
+         *) ;;
+    esac
+
     if [ "0" = "$NO_MODIFY_PATH" ]; then
         add_install_dir_to_ci_path "$_install_dir"
         add_install_dir_to_path "$_install_dir_expr" "$_env_script_path" "$_env_script_path_expr" ".profile" "sh"

cargo-dist/tests/snapshots/axolotlsay_musl_no_gnu.snap

@@ -507,6 +507,12 @@ install() {
 
     say "everything's installed!"
 
+    # Avoid modifying the users PATH if they are managing their PATH manually
+    case :$PATH:
+      in *:$_install_dir:*) NO_MODIFY_PATH=1 ;;
+         *) ;;
+    esac
+
     if [ "0" = "$NO_MODIFY_PATH" ]; then
         add_install_dir_to_ci_path "$_install_dir"
         add_install_dir_to_path "$_install_dir_expr" "$_env_script_path" "$_env_script_path_expr" ".profile" "sh"

cargo-dist/tests/snapshots/axolotlsay_no_homebrew_publish.snap

@@ -485,6 +485,12 @@ install() {
 
     say "everything's installed!"
 
+    # Avoid modifying the users PATH if they are managing their PATH manually
+    case :$PATH:
+      in *:$_install_dir:*) NO_MODIFY_PATH=1 ;;
+         *) ;;
+    esac
+
     if [ "0" = "$NO_MODIFY_PATH" ]; then
         add_install_dir_to_ci_path "$_install_dir"
         add_install_dir_to_path "$_install_dir_expr" "$_env_script_path" "$_env_script_path_expr" ".profile" "sh"