3 files changed, 30 insertions, 8 deletions
diff --git a/src/other_tools/just_mr/cli.hpp b/src/other_tools/just_mr/cli.hpp
index 2174c331..c9a36387 100644
--- a/src/other_tools/just_mr/cli.hpp
+++ b/src/other_tools/just_mr/cli.hpp
@@ -37,6 +37,7 @@ struct MultiRepoCommonArguments {
     std::optional<std::filesystem::path> checkout_locations_file{std::nullopt};
     std::vector<std::string> explicit_distdirs{};
     JustMR::PathsPtr just_mr_paths = std::make_shared<JustMR::Paths>();
+    std::optional<std::vector<std::string>> local_launcher{std::nullopt};
     std::optional<std::filesystem::path> just_path{std::nullopt};
     std::optional<std::string> main{std::nullopt};
     std::optional<std::filesystem::path> rc_path{std::nullopt};
@@ -100,6 +101,18 @@ static inline void SetupMultiRepoCommonArguments(
            "Specification file for checkout locations.")
         ->type_name("CHECKOUT_LOCATION");
     app->add_option_function<std::string>(
+           "--local-launcher",
+           [clargs](auto const& launcher_raw) {
+               clargs->local_launcher =
+                   nlohmann::json::parse(launcher_raw)
+                       .template get<std::vector<std::string>>();
+           },
+           "JSON array with the list of strings representing the launcher to "
+           "prepend actions' commands before being executed locally.")
+        ->type_name("JSON")
+        ->run_callback_for_default()
+        ->default_val(nlohmann::json{"env", "--"}.dump());
+    app->add_option_function<std::string>(
            "--distdir",
            [clargs](auto const& distdir_raw) {
                clargs->explicit_distdirs.emplace_back(
diff --git a/src/other_tools/just_mr/main.cpp b/src/other_tools/just_mr/main.cpp
index 7157034d..b479e1f2 100644
--- a/src/other_tools/just_mr/main.cpp
+++ b/src/other_tools/just_mr/main.cpp
@@ -1241,6 +1241,7 @@ void DefaultReachableRepositories(
 
     bool use_config{false};
     bool use_build_root{false};
+    bool use_launcher{false};
     std::optional<std::filesystem::path> mr_config_path{std::nullopt};
 
     if (subcommand and kKnownJustSubcommands.contains(*subcommand)) {
@@ -1256,6 +1257,7 @@ void DefaultReachableRepositories(
             }
         }
         use_build_root = kKnownJustSubcommands.at(*subcommand).build_root;
+        use_launcher = kKnownJustSubcommands.at(*subcommand).launch;
     }
     // build just command
     std::vector<std::string> cmd = {arguments.common.just_path->string()};
@@ -1270,6 +1272,12 @@ void DefaultReachableRepositories(
         cmd.emplace_back("--local-build-root");
         cmd.emplace_back(*arguments.common.just_mr_paths->root);
     }
+    if (use_launcher and arguments.common.local_launcher and
+        not arguments.common.local_launcher->empty()) {
+        cmd.emplace_back("--local-launcher");
+        cmd.emplace_back(
+            nlohmann::json(*arguments.common.local_launcher).dump());
+    }
     // forward logging arguments
     if (not arguments.log.log_files.empty()) {
         cmd.emplace_back("--log-append");
diff --git a/src/other_tools/just_mr/utils.hpp b/src/other_tools/just_mr/utils.hpp
index f5cc7de9..bfd81f16 100644
--- a/src/other_tools/just_mr/utils.hpp
+++ b/src/other_tools/just_mr/utils.hpp
@@ -48,18 +48,19 @@ std::vector<std::string> const kTakeOver = {"bindings",
 struct JustSubCmdFlags {
     bool config;
     bool build_root;
+    bool launch;
 };
 
 // ordered, so that we have replicability
 std::map<std::string, JustSubCmdFlags> const kKnownJustSubcommands{
-    {"version", {false /*config*/, false /*build_root*/}},
-    {"describe", {true /*config*/, false /*build_root*/}},
-    {"analyse", {true /*config*/, true /*build_root*/}},
-    {"build", {true /*config*/, true /*build_root*/}},
-    {"install", {true /*config*/, true /*build_root*/}},
-    {"rebuild", {true /*config*/, true /*build_root*/}},
-    {"install-cas", {false /*config*/, true /*build_root*/}},
-    {"gc", {false /*config*/, true /*build_root*/}}};
+    {"version", {false /*config*/, false /*build_root*/, false /*launch*/}},
+    {"describe", {true /*config*/, false /*build_root*/, false /*launch*/}},
+    {"analyse", {true /*config*/, true /*build_root*/, false /*launch*/}},
+    {"build", {true /*config*/, true /*build_root*/, true /*launch*/}},
+    {"install", {true /*config*/, true /*build_root*/, true /*launch*/}},
+    {"rebuild", {true /*config*/, true /*build_root*/, true /*launch*/}},
+    {"install-cas", {false /*config*/, true /*build_root*/, false /*launch*/}},
+    {"gc", {false /*config*/, true /*build_root*/, false /*launch*/}}};
 
 nlohmann::json const kDefaultConfigLocations = nlohmann::json::array(
     {{{"root", "workspace"}, {"path", "repos.json"}},