diff --git a/build_single.py b/build_single.py
index 31de840..f3dc1c4 100644
--- a/build_single.py
+++ b/build_single.py
@@ -7,11 +7,14 @@
 
 # Regexes to strip package-relative imports and __main__ blocks
 REL_IMPORT_RE = re.compile(r'^\s*from\s+\.\w+\s+import\s+.*$', re.M)
+COMMON_IMPORT_RE = re.compile(r'^\s*from\s+common\s+import\s+.*$', re.M)
 PKG_IMPORT_RE = re.compile(r'^\s*from\s+machinestate(?:\.\w+)?\s+import\s+.*$', re.M)
 
 def strip_relative_imports(text: str) -> str:
     # Remove "from .X import Y"
     text = REL_IMPORT_RE.sub('', text)
+    # Remove "from common import Y"
+    text = COMMON_IMPORT_RE.sub('', text)
     # Remove "from machinestate(.X)? import Y"
     text = PKG_IMPORT_RE.sub('', text)
     # Also remove "import machinestate" (rare)
@@ -36,7 +39,11 @@ def collect_files(root: pathlib.Path) -> List[str]:
     if common_py.exists():
         files.append(str(common_py))
 
-    files.extend(sorted(glob.glob(str(pkg / "*" / "*.py"))))
+    allfiles = sorted(glob.glob(str(pkg / "*" / "*.py")))
+    for f in allfiles:
+        fname = os.path.basename(str(f))
+        if not fname.startswith("test_"):
+           files.append(str(f))
 
     script_py = pkg / "script.py"
     if script_py.exists():
@@ -77,4 +84,4 @@ def main():
     print(f"[ok] wrote {OUT} ({out_path.stat().st_size} bytes)")
 
 if __name__ == "__main__":
-    main()
\ No newline at end of file
+    main()
diff --git a/machinestate_pkg/ModulesInfo/ModulesInfo.py b/machinestate_pkg/ModulesInfo/ModulesInfo.py
index 52e0799..1feed1e 100644
--- a/machinestate_pkg/ModulesInfo/ModulesInfo.py
+++ b/machinestate_pkg/ModulesInfo/ModulesInfo.py
@@ -1,4 +1,4 @@
-from .common import InfoGroup, which, re, os
+from common import InfoGroup, which, re, os
 
 ################################################################################
 # Infos about loaded modules in the modules system
@@ -9,8 +9,11 @@ def __init__(self, extended=False, anonymous=False, modulecmd="modulecmd"):
         super(ModulesInfo, self).__init__(name="ModulesInfo",
                                           extended=extended,
                                           anonymous=anonymous)
+        if os.getenv("MODULES_CMD"):
+            modulecmd = os.getenv("MODULES_CMD")
         if os.getenv("LMOD_CMD"):
             modulecmd = os.getenv("LMOD_CMD")
+
         self.modulecmd = modulecmd
         parse = ModulesInfo.parsemodules
         cmd_opts = "sh -t list 2>&1"
@@ -37,4 +40,6 @@ def parsemodules(value):
             slist = [ x.split("'")[1] for x in re.split("\n", value) if "echo" in x and "'" in x ]
         if re.match("^Currently Loaded.+$", slist[0]):
             slist = slist[1:]
-        return slist
\ No newline at end of file
+        if re.match("^No Modulefiles Currently Loaded.+$", slist[0]):
+            slist = slist[1:]
+        return slist
diff --git a/machinestate_pkg/ModulesInfo/test_ModulesInfo.py b/machinestate_pkg/ModulesInfo/test_ModulesInfo.py
new file mode 100644
index 0000000..fdd7cf3
--- /dev/null
+++ b/machinestate_pkg/ModulesInfo/test_ModulesInfo.py
@@ -0,0 +1,47 @@
+#!/usr/bin/env python3
+
+import sys, os, os.path
+sys.path.append("..")
+
+from locale import getpreferredencoding
+ENCODING = getpreferredencoding()
+
+import unittest
+
+import ModulesInfo
+
+def readfile(filename):
+    data = None
+    if os.path.exists(filename):
+        with open(filename, 'rb') as filefp:
+            data = filefp.read().decode(ENCODING)
+    return data
+
+basedir = "./tests"
+
+
+def runtest(self, testfolder):
+    os.environ["MODULES_CMD"] = os.path.join(basedir, "fakemodules.sh")
+    c = ModulesInfo.ModulesInfo(modulecmd=os.path.join(basedir, "fakemodules.sh"))
+    c.generate()
+    os.environ["FAKEMODULES_INPUT"] = os.path.join(testfolder, "input")
+    c.update()
+    j = c.get_json()
+    ref = readfile(os.path.join(testfolder, "output"))
+    self.assertEqual(ref.strip(), j.strip())
+    if ref.strip() != j.strip():
+        print(j.strip())
+
+
+class TestModulesInfo(unittest.TestCase):
+    def test_tcl_5_0_1(self):
+        runtest(self, os.path.join(basedir, "tcl_5.0.1"))
+    def test_tcl_5_5_0(self):
+        runtest(self, os.path.join(basedir, "tcl_5.5.0"))
+    def test_tcl_5_5_0_empty(self):
+        runtest(self, os.path.join(basedir, "tcl_5.5.0_empty"))
+    def test_tcl_5_6_0(self):
+        runtest(self, os.path.join(basedir, "tcl_5.6.0"))
+
+if __name__ == '__main__':
+    unittest.main()
diff --git a/machinestate_pkg/ModulesInfo/tests/fakemodules.sh b/machinestate_pkg/ModulesInfo/tests/fakemodules.sh
new file mode 100755
index 0000000..acc555d
--- /dev/null
+++ b/machinestate_pkg/ModulesInfo/tests/fakemodules.sh
@@ -0,0 +1,8 @@
+#!/bin/bash
+
+INP=${FAKEMODULES_INPUT}
+if [ -z ${INP} ]; then
+    exit 1
+fi
+
+cat ${INP}
diff --git a/machinestate_pkg/ModulesInfo/tests/tcl_5.0.1/input b/machinestate_pkg/ModulesInfo/tests/tcl_5.0.1/input
new file mode 100644
index 0000000..382ccf4
--- /dev/null
+++ b/machinestate_pkg/ModulesInfo/tests/tcl_5.0.1/input
@@ -0,0 +1,5 @@
+Currently Loaded Modulefiles:
+intel/2021.4.0
+intelmpi/2021.6.0
+scorep/7.1-intel-2021.4.0-intelmpi-2021.4.0
+scalasca/2.6-intel-2021.4.0-intelmpi-2021.4.0
diff --git a/machinestate_pkg/ModulesInfo/tests/tcl_5.0.1/output b/machinestate_pkg/ModulesInfo/tests/tcl_5.0.1/output
new file mode 100644
index 0000000..2f8f668
--- /dev/null
+++ b/machinestate_pkg/ModulesInfo/tests/tcl_5.0.1/output
@@ -0,0 +1,9 @@
+{
+    "Loaded": [
+        "intel/2021.4.0",
+        "intelmpi/2021.6.0",
+        "scorep/7.1-intel-2021.4.0-intelmpi-2021.4.0",
+        "scalasca/2.6-intel-2021.4.0-intelmpi-2021.4.0"
+    ],
+    "_meta": "ModulesInfo(modulecmd='./tests/fakemodules.sh')"
+}
diff --git a/machinestate_pkg/ModulesInfo/tests/tcl_5.5.0/input b/machinestate_pkg/ModulesInfo/tests/tcl_5.5.0/input
new file mode 100644
index 0000000..e1da355
--- /dev/null
+++ b/machinestate_pkg/ModulesInfo/tests/tcl_5.5.0/input
@@ -0,0 +1,4 @@
+Currently Loaded Modulefiles:
+openmpi/5.0.5-gcc13.3.0
+fftw/3.3.10-gcc13.3.0-openmpi
+python/3.12-conda
diff --git a/machinestate_pkg/ModulesInfo/tests/tcl_5.5.0/output b/machinestate_pkg/ModulesInfo/tests/tcl_5.5.0/output
new file mode 100644
index 0000000..8b08002
--- /dev/null
+++ b/machinestate_pkg/ModulesInfo/tests/tcl_5.5.0/output
@@ -0,0 +1,8 @@
+{
+    "Loaded": [
+        "openmpi/5.0.5-gcc13.3.0",
+        "fftw/3.3.10-gcc13.3.0-openmpi",
+        "python/3.12-conda"
+    ],
+    "_meta": "ModulesInfo(modulecmd='./tests/fakemodules.sh')"
+}
diff --git a/machinestate_pkg/ModulesInfo/tests/tcl_5.5.0_empty/input b/machinestate_pkg/ModulesInfo/tests/tcl_5.5.0_empty/input
new file mode 100644
index 0000000..a0ea85e
--- /dev/null
+++ b/machinestate_pkg/ModulesInfo/tests/tcl_5.5.0_empty/input
@@ -0,0 +1 @@
+No Modulefiles Currently Loaded.
diff --git a/machinestate_pkg/ModulesInfo/tests/tcl_5.5.0_empty/output b/machinestate_pkg/ModulesInfo/tests/tcl_5.5.0_empty/output
new file mode 100644
index 0000000..f098182
--- /dev/null
+++ b/machinestate_pkg/ModulesInfo/tests/tcl_5.5.0_empty/output
@@ -0,0 +1,4 @@
+{
+    "Loaded": [],
+    "_meta": "ModulesInfo(modulecmd='./tests/fakemodules.sh')"
+}
diff --git a/machinestate_pkg/ModulesInfo/tests/tcl_5.6.0/input b/machinestate_pkg/ModulesInfo/tests/tcl_5.6.0/input
new file mode 100644
index 0000000..0ccaab7
--- /dev/null
+++ b/machinestate_pkg/ModulesInfo/tests/tcl_5.6.0/input
@@ -0,0 +1,5 @@
+Currently Loaded Modulefiles:
+intel/2025.0.0
+intelmpi/2021.14.0
+cuda/12.9.0
+likwid/5.5.1-cuda
diff --git a/machinestate_pkg/ModulesInfo/tests/tcl_5.6.0/output b/machinestate_pkg/ModulesInfo/tests/tcl_5.6.0/output
new file mode 100644
index 0000000..083b64a
--- /dev/null
+++ b/machinestate_pkg/ModulesInfo/tests/tcl_5.6.0/output
@@ -0,0 +1,9 @@
+{
+    "Loaded": [
+        "intel/2025.0.0",
+        "intelmpi/2021.14.0",
+        "cuda/12.9.0",
+        "likwid/5.5.1-cuda"
+    ],
+    "_meta": "ModulesInfo(modulecmd='./tests/fakemodules.sh')"
+}