deprecate running EasyBuild with Python 2.6 via new check_python_version() function

Author: boegel

easybuild/tools/options.py

@@ -93,7 +93,8 @@
 from easybuild.tools.package.utilities import avail_package_naming_schemes
 from easybuild.tools.toolchain.compiler import DEFAULT_OPT_LEVEL, OPTARCH_MAP_CHAR, OPTARCH_SEP, Compiler
 from easybuild.tools.repository.repository import avail_repositories
-from easybuild.tools.systemtools import get_cpu_architecture, get_cpu_family, get_cpu_features, get_system_info
+from easybuild.tools.systemtools import check_python_version, get_cpu_architecture, get_cpu_family, get_cpu_features
+from easybuild.tools.systemtools import get_system_info
 from easybuild.tools.version import this_is_easybuild
 
 
@@ -1302,6 +1303,7 @@ def set_up_configuration(args=None, logfile=None, testing=False, silent=False):
     :param testing: enable testing mode
     :param silent: stay silent (no printing)
     """
+    check_python_version()
 
     # set up fake 'vsc' Python package, to catch easyblocks/scripts that still import from vsc.* namespace
     # this must be done early on, to catch imports from the vsc namespace in modules included via --include-*

easybuild/tools/systemtools.py

@@ -802,3 +802,29 @@ def det_terminal_size():
             height, width = 25, 80
 
     return height, width
+
+
+def check_python_version():
+    """Check currently used Python version."""
+    python_maj_ver = sys.version_info[0]
+    python_min_ver = sys.version_info[1]
+    python_ver = '%d.%d' % (python_maj_ver, python_min_ver)
+    _log.info("Found Python version %s", python_ver)
+
+    if python_maj_ver == 2:
+        if python_min_ver < 6:
+            raise EasyBuildError("Python 2.6 or higher is required when using Python 2, found Python %s", python_ver)
+        elif python_min_ver == 6:
+            _log.deprecated("Running EasyBuild with Python 2.6 is deprecated", '5.0')
+        else:
+            _log.info("Running EasyBuild with Python 2 (version %s)", python_ver)
+
+    elif python_maj_ver == 3:
+        if python_min_ver < 5:
+            raise EasyBuildError("Python 3.5 or higher is required when using Python 3, found Python %s", python_ver)
+        else:
+            _log.info("Running EasyBuild with Python 3 (version %s)", python_ver)
+    else:
+        raise EasyBuildError("EasyBuild is not compatible (yet) with Python %s", python_ver)
+
+    return (python_maj_ver, python_min_ver)

test/framework/systemtools.py

@@ -35,17 +35,19 @@
 from unittest import TextTestRunner
 
 import easybuild.tools.systemtools as st
+from easybuild.tools.build_log import EasyBuildError
 from easybuild.tools.filetools import read_file
 from easybuild.tools.py2vs3 import string_type
 from easybuild.tools.run import run_cmd
 from easybuild.tools.systemtools import CPU_ARCHITECTURES, AARCH32, AARCH64, POWER, X86_64
 from easybuild.tools.systemtools import CPU_FAMILIES, POWER_LE, DARWIN, LINUX, UNKNOWN
 from easybuild.tools.systemtools import CPU_VENDORS, AMD, APM, ARM, CAVIUM, IBM, INTEL
 from easybuild.tools.systemtools import MAX_FREQ_FP, PROC_CPUINFO_FP, PROC_MEMINFO_FP
+from easybuild.tools.systemtools import check_python_version
 from easybuild.tools.systemtools import det_parallelism, get_avail_core_count, get_cpu_architecture, get_cpu_family
 from easybuild.tools.systemtools import get_cpu_features, get_cpu_model, get_cpu_speed, get_cpu_vendor
-from easybuild.tools.systemtools import get_glibc_version, get_os_type, get_os_name, get_os_version, get_platform_name
-from easybuild.tools.systemtools import get_shared_lib_ext, get_system_info, get_total_memory, get_gcc_version
+from easybuild.tools.systemtools import get_gcc_version, get_glibc_version, get_os_type, get_os_name, get_os_version
+from easybuild.tools.systemtools import get_platform_name, get_shared_lib_ext, get_system_info, get_total_memory
 
 
 PROC_CPUINFO_TXT = None
@@ -335,6 +337,7 @@ def setUp(self):
         self.orig_run_cmd = st.run_cmd
         self.orig_platform_uname = st.platform.uname
         self.orig_get_tool_version = st.get_tool_version
+        self.orig_sys_version_info = st.sys.version_info
 
     def tearDown(self):
         """Cleanup after systemtools test."""
@@ -345,6 +348,7 @@ def tearDown(self):
         st.run_cmd = self.orig_run_cmd
         st.platform.uname = self.orig_platform_uname
         st.get_tool_version = self.orig_get_tool_version
+        st.sys.version_info = self.orig_sys_version_info
         super(SystemToolsTest, self).tearDown()
 
     def test_avail_core_count_native(self):
@@ -767,6 +771,70 @@ def test_det_terminal_size(self):
         self.assertTrue(isinstance(height, int) and height >= 0)
         self.assertTrue(isinstance(width, int) and width >= 0)
 
+    def test_check_python_version(self):
+        """Test check_python_version function."""
+
+        def mock_python_ver(py_maj_ver, py_min_ver):
+            """Helper function to mock a particular Python version."""
+            st.sys.version_info = (py_maj_ver, py_min_ver) + sys.version_info[2:]
+
+        # mock running with different Python versions
+        mock_python_ver(1, 4)
+        error_pattern = r"EasyBuild is not compatible \(yet\) with Python 1.4"
+        self.assertErrorRegex(EasyBuildError, error_pattern, check_python_version)
+
+        mock_python_ver(4, 0)
+        error_pattern = r"EasyBuild is not compatible \(yet\) with Python 4.0"
+        self.assertErrorRegex(EasyBuildError, error_pattern, check_python_version)
+
+        mock_python_ver(2, 5)
+        error_pattern = r"Python 2.6 or higher is required when using Python 2, found Python 2.5"
+        self.assertErrorRegex(EasyBuildError, error_pattern, check_python_version)
+
+        # no problems when running with a supported Python version
+        for pyver in [(2, 7), (3, 5), (3, 6), (3, 7)]:
+            mock_python_ver(*pyver)
+            self.assertEqual(check_python_version(), pyver)
+
+        mock_python_ver(2, 6)
+        # deprecation warning triggers an error in test environment
+        error_pattern = r"Running EasyBuild with Python 2.6 is deprecated"
+        self.assertErrorRegex(EasyBuildError, error_pattern, check_python_version)
+
+        # we may trigger a deprecation warning below (when testing with Python 2.6)
+        py26_depr_warning = "\nWARNING: Deprecated functionality, will no longer work in v5.0: "
+        py26_depr_warning += "Running EasyBuild with Python 2.6 is deprecated"
+
+        self.allow_deprecated_behaviour()
+
+        # first test with mocked Python 2.6
+        self.mock_stderr(True)
+        check_python_version()
+        stderr = self.get_stderr()
+        self.mock_stderr(False)
+
+        # we should always get a deprecation warning here
+        self.assertTrue(stderr.startswith(py26_depr_warning))
+
+        # restore Python version info to check with Python version used to run tests
+        st.sys.version_info = self.orig_sys_version_info
+
+        # shouldn't raise any errors, since Python version used to run tests should be supported;
+        self.mock_stderr(True)
+        (py_maj_ver, py_min_ver) = check_python_version()
+        stderr = self.get_stderr()
+        self.mock_stderr(False)
+
+        self.assertTrue(py_maj_ver in [2, 3])
+        if py_maj_ver == 2:
+            self.assertTrue(py_min_ver in [6, 7])
+        else:
+            self.assertTrue(py_min_ver >= 5)
+
+        # only deprecation warning when actually testing with Python 2.6
+        if sys.version_info[:2] == (2, 6):
+            self.assertTrue(stderr.startswith(py26_depr_warning))
+
 
 def suite():
     """ returns all the testcases in this module """