catalyst: Rewrite ismount() to use libmount

libmount is provided by util-linux, so this adds a dependency on
sys-apps/util-linux[python]. A later patch will make more extensive use
of this API.

Signed-off-by: Matt Turner <mattst88@gentoo.org>

3 files changed, 8 insertions, 10 deletions

diff --git a/README b/README
index 1cceb63e..594de9e1 100644
--- a/README
+++ b/README
@@ -17,7 +17,7 @@ simple and reproducable manner. Use at your own risk.
 Requirements
 =======================
 
-- Python 3.6 or greater
+- Python 3.8 or greater
 - A generic stage3 tarball for your architecture
 - A squashfs ebuild repository snapshot
   - Or an ebuild git repo with sys-fs/squashfs-tools-ng and dev-vcs/git
diff --git a/catalyst/support.py b/catalyst/support.py
index 4458ed20..ddbd9ab9 100644
--- a/catalyst/support.py
+++ b/catalyst/support.py
@@ -8,6 +8,8 @@ import time
 from pathlib import Path
 from subprocess import Popen
 
+import libmount
+
 from catalyst import log
 
 BASH_BINARY = "/bin/bash"
@@ -182,15 +184,13 @@ def read_makeconf(mymakeconffile):
 
 def ismount(path):
     """Like os.path.ismount, but also support bind mounts"""
-    if os.path.ismount(path):
+    path = Path(path)
+    if path.is_mount():
         return True
 
-    a = os.popen("mount")
-    mylines = a.readlines()
-    a.close()
-    for line in mylines:
-        mysplit = line.split()
-        if Path(path) == Path(mysplit[2]):
+    cxt = libmount.Context()
+    while (fs := cxt.mtab.next_fs()) is not None:
+        if path == Path(fs.target):
             return True
 
     return False
diff --git a/setup.py b/setup.py
index 7a97b30c..fc1ac005 100755
--- a/setup.py
+++ b/setup.py
@@ -101,8 +101,6 @@ _setup(
         'Topic :: System :: Installation/Setup',
         'Topic :: System :: Software Distribution',
         'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.6',
-        'Programming Language :: Python :: 3.7',
         'Programming Language :: Python :: 3.8',
     ],
     scripts=['bin/{0}'.format(_package_name)],