added testcase

Change-Id: Ie793d88098f20dc622f398334a77f63cacfe982d

libmamba/src/api/install.cpp

@@ -589,16 +589,16 @@ namespace mamba
             );
         }
 
-	std::vector<LockFile> locks;
+        std::vector<LockFile> locks;
 
-	for (auto& c : ctx.pkgs_dirs)
-	{
-	    locks.push_back(LockFile(c));
-	}
+        for (auto& c : ctx.pkgs_dirs)
+        {
+            locks.push_back(LockFile(c));
+        }
 
         MTransaction trans(pool, solver, package_caches);
-        
-	if (ctx.output_params.json)
+
+        if (ctx.output_params.json)
         {
             trans.log_json();
         }
@@ -662,15 +662,15 @@ namespace mamba
             // Note that the Transaction will gather the Solvables,
             // so they must have been ready in the pool before this line
             auto transaction = create_transaction(pool, pkg_caches, others);
-	    
-	    std::vector<LockFile> lock_pkgs;
-	    
-	    for (auto& c : ctx.pkgs_dirs)
-	    {
-		lock_pkgs.push_back(LockFile(c));
-	    }
-            
-	    if (ctx.output_params.json)
+
+            std::vector<LockFile> lock_pkgs;
+
+            for (auto& c : ctx.pkgs_dirs)
+            {
+                lock_pkgs.push_back(LockFile(c));
+            }
+
+            if (ctx.output_params.json)
             {
                 transaction.log_json();
             }

micromamba/tests/test_create.py

@@ -340,6 +340,34 @@ def test_multiple_spec_files(tmp_home, tmp_root_prefix, tmp_path, type):
             assert res["specs"] == [explicit_specs[0]]
 
 
+def test_multiprocessing():
+    if platform.system() == "Windows":
+        return
+
+    root_prefix = Path(os.environ["MAMBA_ROOT_PREFIX"])
+    if os.path.exists(root_prefix / "pkgs"):
+        shutil.rmtree(root_prefix / "pkgs")
+
+    cmd = [helpers.get_umamba()]
+    cmd += ["create", "-n", "env1", "-y"]
+    cmd += ["airflow"]
+    cmd += ["pytorch"]
+    cmd += ["-c", "conda-forge"]
+
+    cmd2 = [helpers.get_umamba(), "create"]
+    cmd2 += ["-n", "env2", "-y"]
+    cmd2 += ["airflow"]
+    cmd2 += ["pytorch"]
+    cmd2 += ["-c", "conda-forge"]
+
+    # must not crash
+    cmds = [cmd, cmd2]
+    procs = [subprocess.Popen(p) for p in cmds]
+    for p in procs:
+        rc = p.wait()
+        assert rc == 0
+
+
 @pytest.mark.skipif(
     helpers.dry_run_tests is helpers.DryRun.ULTRA_DRY,
     reason="Running only ultra-dry tests",