Over at https://launchpadlibrarian.net/550715513/buildlog_ubuntu-hirsute-amd64.virtualbox_6.1.22-dfsg-2~ubuntu1.21.04.2_BUILDING.txt.gz
I have rebuilt an earlier version of virtualbox, that sets Rules-Requires-Root: no and added extra ls statements to find where/when/why setuid bits are getting lost after fixperms.
make[1]: Leaving directory '/<<PKGBUILDDIR>>'
debian/rules override_dh_strip
make[1]: Entering directory '/<<PKGBUILDDIR>>'
ls -latr debian/virtualbox/usr/lib/virtualbox/VBoxSDL
-rwsr-sr-x 1 buildd buildd 406808 Jul 29 14:34 debian/virtualbox/usr/lib/virtualbox/VBoxSDL
...
dh_strip --dbgsym-migration='virtualbox-dbg'
debugedit: debian/virtualbox/usr/lib/virtualbox/VBoxSDL.so: Unknown DWARF DW_FORM_0x1f20
a7cf3c43c8b18c3261d2d4737a475bf730ad1554
ls -latr debian/virtualbox/usr/lib/virtualbox/VBoxSDL
-rwxr-xr-x 1 buildd buildd 166208 Jul 29 14:35 debian/virtualbox/usr/lib/virtualbox/VBoxSDL
It seems to me that either dh_strip or something it calls (strip, debugedit) looses the setuid permission in hirsute and up.
I updated debugedit to 5.0 version, the changelog looks like adding some errors when chmod can't be done correctly
@@ -3419,7 +3431,8 @@
}
/* Make sure we can read and write */
- chmod (file, stat_buf.st_mode | S_IRUSR | S_IWUSR);
+ if (chmod (file, stat_buf.st_mode | S_IRUSR | S_IWUSR) != 0)
+ error (0, errno, "Failed to chmod input file '%s' to make sure we can read and write", file);
fd = open (file, O_RDWR);
if (fd < 0)
@@ -3635,7 +3648,8 @@
close (fd);
/* Restore old access rights */
- chmod (file, stat_buf.st_mode);
+ if (chmod (file, stat_buf.st_mode) != 0)
+ error (0, errno, "Failed to chmod input file '%s' to restore old access rights", file);
free ((char *) dso->filename);
destroy_strings (&dso->debug_str);
@@ -349,7 +352,8 @@
}
/* Make sure we can read and write */
- chmod (fname, stat_buf.st_mode | S_IRUSR | S_IWUSR);
+ if (chmod (fname, stat_buf.st_mode | S_IRUSR | S_IWUSR) != 0)
+ error (0, errno, _("cannot chmod \"%s\" to make sure we can read and write"), fname);
bool failed = false;
int fd = open64 (fname, O_RDWR);
@@ -386,7 +390,8 @@
}
/* Restore old access rights. Including any suid bits reset. */
- chmod (fname, stat_buf.st_mode);
+ if (chmod (fname, stat_buf.st_mode) != 0)
+ error (0, errno, _("cannot chmod \"%s\" to restore old access rights"), fname);
if (failed)
failed_count++;
and similar.