diff --git a/conans/client/cmd/build.py b/conans/client/cmd/build.py
index 6cda8eb6c04..1a4207bfabf 100644
--- a/conans/client/cmd/build.py
+++ b/conans/client/cmd/build.py
@@ -12,7 +12,7 @@
 def cmd_build(app, conanfile_path, base_path, source_folder, build_folder, package_folder,
               install_folder, test=False, should_configure=True, should_build=True,
               should_install=True, should_test=True, layout_source_folder=None,
-              layout_build_folder=None):
+              layout_build_folder=None, conf=None):
     """ Call to build() method saved on the conanfile.py
     param conanfile_path: path to a conanfile.py
     """
@@ -29,6 +29,8 @@ def cmd_build(app, conanfile_path, base_path, source_folder, build_folder, packa
                              "requirements and generators from '%s' file"
                              % (CONANFILE, CONANFILE, CONANFILE_TXT))
 
+    if conf:
+        conan_file.conf.compose_conf(conf)
     if test:
         try:
             conan_file.requires.add_ref(test)
diff --git a/conans/client/cmd/test.py b/conans/client/cmd/test.py
index 4c2f580dd60..996ff39b1c2 100644
--- a/conans/client/cmd/test.py
+++ b/conans/client/cmd/test.py
@@ -32,7 +32,7 @@ def install_build_and_test(app, conanfile_abs_path, reference, graph_info,
     if build_modes is None:
         build_modes = ["never"]
     try:
-        install_folder = deps_install(app=app,
+        install_folder, conanfile = deps_install(app=app,
                                       create_reference=reference,
                                       ref_or_path=conanfile_abs_path,
                                       install_folder=test_build_folder,
@@ -53,7 +53,7 @@ def install_build_and_test(app, conanfile_abs_path, reference, graph_info,
         cmd_build(app, conanfile_abs_path, test_build_folder,
                   source_folder=base_folder, build_folder=test_build_folder,
                   package_folder=os.path.join(test_build_folder, "package"),
-                  install_folder=install_folder, test=reference)
+                  install_folder=install_folder, test=reference, conf=conanfile.conf)
     finally:
         if delete_after_build:
             # Required for windows where deleting the cwd is not possible.
diff --git a/conans/client/manager.py b/conans/client/manager.py
index f27fba83241..d0160ce5ca1 100644
--- a/conans/client/manager.py
+++ b/conans/client/manager.py
@@ -146,4 +146,4 @@ def deps_install(app, ref_or_path, install_folder, base_folder, graph_info, remo
             if hasattr(deploy_conanfile, "deploy") and callable(deploy_conanfile.deploy):
                 run_deploy(deploy_conanfile, install_folder)
 
-    return install_folder
+    return install_folder, conanfile
diff --git a/conans/test/integration/toolchains/env/test_virtualenv_winbash.py b/conans/test/integration/toolchains/env/test_virtualenv_winbash.py
index e79fdbd0f23..dc231f5d85e 100644
--- a/conans/test/integration/toolchains/env/test_virtualenv_winbash.py
+++ b/conans/test/integration/toolchains/env/test_virtualenv_winbash.py
@@ -1,9 +1,11 @@
 import os
 import platform
+import textwrap
 
 import pytest
 
 from conans.test.assets.genconanfile import GenConanfile
+from conans.test.conftest import tools_locations
 from conans.test.utils.tools import TestClient
 from conans.tools import save
 
@@ -166,3 +168,54 @@ def test_nowinbash_virtual_cygwin(client):
     assert not os.path.exists(os.path.join(client.current_folder, "conanrunenv.bat"))
     run_contents = client.load("conanrunenv.sh")
     assert 'export RUNTIME_VAR="/cygdrive/c/path/to/exe"' in run_contents
+
+
+@pytest.mark.skipif(platform.system() != "Windows", reason="Requires Windows")
+@pytest.mark.tool_msys2
+def test_conf_inherited_in_test_package():
+    client = TestClient()
+    bash_path = tools_locations["msys2"]["system"]["path"]["Windows"] + "/bash.exe"
+    conanfile = textwrap.dedent("""
+            from conan import ConanFile
+
+            class Recipe(ConanFile):
+                name="msys2"
+                version="1.0"
+
+                def package_info(self):
+                    self.conf_info.define("tools.microsoft.bash:subsystem", "msys2")
+                    self.conf_info.define("tools.microsoft.bash:path", "{}")
+    """.format(bash_path))
+    client.save({"conanfile.py": conanfile})
+    client.run("create .")
+
+    conanfile = textwrap.dedent("""
+                from conan import ConanFile
+
+                class Recipe(ConanFile):
+                    name="consumer"
+                    version="1.0"
+        """)
+    test_package = textwrap.dedent("""
+                    from conan import ConanFile
+
+                    class Recipe(ConanFile):
+                        name="test"
+                        version="1.0"
+                        win_bash = True
+
+                        def build_requirements(self):
+                            self.tool_requires(self.tested_reference_str)
+                            self.tool_requires("msys2/1.0")
+
+                        def build(self):
+                            self.output.warning(self.conf.get("tools.microsoft.bash:subsystem"))
+                            self.run("aclocal --version")
+
+                        def test(self):
+                            pass
+            """)
+    client.save({"conanfile.py": conanfile, "test_package/conanfile.py": test_package})
+    client.run("create . -s:b os=Windows -s:h os=Windows")
+    assert "are needed to run commands in a Windows subsystem" not in client.out
+    assert "aclocal (GNU automake)" in client.out