add option to relocate prefix. (#2385)

add option to relocate prefix

libmamba/include/mamba/core/context.hpp

@@ -129,6 +129,7 @@ namespace mamba
         fs::u8path target_prefix;
         fs::u8path root_prefix;
         fs::u8path conda_prefix;
+        fs::u8path relocate_prefix;
 
         // TODO check writable and add other potential dirs
         std::vector<fs::u8path> envs_dirs;

libmamba/include/mamba/core/transaction_context.hpp

@@ -39,12 +39,20 @@ namespace mamba
             const std::pair<std::string, std::string>& py_versions,
             const std::vector<MatchSpec>& requested_specs
         );
+
+        TransactionContext(
+            const fs::u8path& target_prefix,
+            const fs::u8path& relocate_prefix,
+            const std::pair<std::string, std::string>& py_versions,
+            const std::vector<MatchSpec>& requested_specs
+        );
         ~TransactionContext();
         bool try_pyc_compilation(const std::vector<fs::u8path>& py_files);
         void wait_for_pyc_compilation();
 
         bool has_python;
         fs::u8path target_prefix;
+        fs::u8path relocate_prefix;
         fs::u8path site_packages_path;
         fs::u8path python_path;
         std::string python_version;

libmamba/src/api/configuration.cpp

@@ -1036,6 +1036,13 @@ namespace mamba
                    .set_post_merge_hook(detail::target_prefix_hook)
                    .set_post_context_hook(detail::post_target_prefix_rc_loading));
 
+        insert(Configurable("relocate_prefix", &ctx.relocate_prefix)
+                   .group("Basic")
+                   .set_env_var_names()
+                   .needs({ "target_prefix" })
+                   .set_single_op_lifetime()
+                   .description("Path to the relocation prefix"));
+
         insert(Configurable("use_target_prefix_fallback", true)
                    .group("Basic")
                    .set_single_op_lifetime()

libmamba/src/core/link.cpp

@@ -157,7 +157,7 @@ namespace mamba
         fs::u8path python_path;
         if (m_context->has_python)
         {
-            python_path = m_context->target_prefix / m_context->python_path;
+            python_path = m_context->relocate_prefix / m_context->python_path;
         }
         if (!python_path.empty())
         {
@@ -614,7 +614,7 @@ namespace mamba
         {
             // we have to replace the PREFIX stuff in the data
             // and copy the file
-            std::string new_prefix = m_context->target_prefix.string();
+            std::string new_prefix = m_context->relocate_prefix.string();
 #ifdef _WIN32
             replace_all(new_prefix, "\\", "/");
 #endif

libmamba/src/core/transaction.cpp

@@ -576,6 +576,7 @@ namespace mamba
 
         m_transaction_context = TransactionContext(
             Context::instance().target_prefix,
+            Context::instance().relocate_prefix,
             find_python_version(),
             specs_to_install
         );
@@ -669,6 +670,7 @@ namespace mamba
 
         m_transaction_context = TransactionContext(
             Context::instance().target_prefix,
+            Context::instance().relocate_prefix,
             find_python_version(),
             solver.install_specs()
         );
@@ -815,6 +817,7 @@ namespace mamba
 
         m_transaction_context = TransactionContext(
             Context::instance().target_prefix,
+            Context::instance().relocate_prefix,
             find_python_version(),
             specs_to_install
         );

libmamba/src/core/transaction_context.cpp

@@ -101,6 +101,7 @@ namespace mamba
     )
         : has_python(py_versions.first.size() != 0)
         , target_prefix(ltarget_prefix)
+        , relocate_prefix(ltarget_prefix)
         , python_version(py_versions.first)
         , old_python_version(py_versions.second)
         , requested_specs(lrequested_specs)
@@ -133,12 +134,31 @@ namespace mamba
         }
     }
 
+    TransactionContext::TransactionContext(
+        const fs::u8path& ltarget_prefix,
+        const fs::u8path& lrelocate_prefix,
+        const std::pair<std::string, std::string>& py_versions,
+        const std::vector<MatchSpec>& lrequested_specs
+    )
+        : TransactionContext(ltarget_prefix, py_versions, lrequested_specs)
+    {
+        if (lrelocate_prefix.empty())
+        {
+            relocate_prefix = ltarget_prefix;
+        }
+        else
+        {
+            relocate_prefix = lrelocate_prefix;
+        }
+    }
+
     TransactionContext& TransactionContext::operator=(const TransactionContext& other)
     {
         if (this != &other)
         {
             has_python = other.has_python;
             target_prefix = other.target_prefix;
+            relocate_prefix = other.relocate_prefix;
             python_version = other.python_version;
             old_python_version = other.old_python_version;
             requested_specs = other.requested_specs;

micromamba/src/common_options.cpp

@@ -118,6 +118,15 @@ init_prefix_options(CLI::App* subcom)
     subcom->add_option("-p,--prefix", prefix.get_cli_config<fs::u8path>(), prefix.description())
         ->group(cli_group);
 
+    auto& relocate_prefix = config.at("relocate_prefix");
+    subcom
+        ->add_option(
+            "--relocate-prefix",
+            relocate_prefix.get_cli_config<fs::u8path>(),
+            relocate_prefix.description()
+        )
+        ->group(cli_group);
+
     auto& name = config.at("env_name");
     subcom->add_option("-n,--name", name.get_cli_config<std::string>(), name.description())
         ->group(cli_group);

micromamba/tests/test_create.py

@@ -31,7 +31,6 @@
 
 
 class TestCreate:
-
     current_root_prefix = os.environ["MAMBA_ROOT_PREFIX"]
     current_prefix = os.environ["CONDA_PREFIX"]
 
@@ -475,7 +474,6 @@ def test_explicit_specs(self, valid, existing_cache):
     @pytest.mark.parametrize("prefix_selector", [None, "prefix", "name"])
     @pytest.mark.parametrize("create_cmd", ["create", "env create"])
     def test_create_empty(self, prefix_selector, existing_cache, create_cmd):
-
         if prefix_selector == "name":
             cmd = ("-n", TestCreate.env_name, "--json")
         elif prefix_selector == "prefix":
@@ -493,6 +491,26 @@ def test_create_empty(self, prefix_selector, existing_cache, create_cmd):
 
         assert Path(os.path.join(TestCreate.prefix, "conda-meta", "history")).exists()
 
+    @pytest.mark.skipif(
+        dry_run_tests is DryRun.ULTRA_DRY, reason="Running only ultra-dry tests"
+    )
+    @pytest.mark.parametrize("relocate_prefix", ["/home/bob/env", "/"])
+    def test_create_with_relocate_prefix(self, relocate_prefix, existing_cache):
+        res = create(
+            "-p",
+            TestCreate.prefix,
+            "--relocate-prefix",
+            relocate_prefix,
+            "python=3.11",
+            "--json",
+            no_dry_run=True,
+        )
+        assert res["success"]
+        if platform.system() != "Windows":
+            with open(Path(TestCreate.prefix) / "bin" / "2to3") as f:
+                firstline = f.readline()
+                assert firstline == f"#!{relocate_prefix}/bin/python3.11\n"
+
     @pytest.mark.skipif(
         dry_run_tests is DryRun.ULTRA_DRY, reason="Running only ultra-dry tests"
     )