A customer got the following traceback in tl-setup.log when the apt-backend failed to parse /etc/apt/sources.list: 2020-04-01 13:52:14,461: *** tl-setup started *** 2020-04-01 13:52:14,461: Architecture: x86_64 2020-04-01 13:52:14,461: Distribution: Ubuntu 2020-04-01 13:52:14,461: Distribution version: 12.04 2020-04-01 13:52:14,461: Distribution family: Ubuntu 2020-04-01 13:52:14,461: Package format: deb 2020-04-01 13:52:14,461: Creating /usr/bin/python-thinlinc 2020-04-01 13:52:14,461: Creating /usr/bin/thinlinc-login 2020-04-01 13:52:14,895: Traceback (most recent call last): 2020-04-01 13:52:14,896: File "/opt/thinlinc/sbin/../libexec/tl-setup.py", line 308, in <module> 2020-04-01 13:52:14,896: Oo0O0OOOoo ( ) 2020-04-01 13:52:14,896: File "/opt/thinlinc/sbin/../libexec/tl-setup.py", line 265, in Oo0O0OOOoo 2020-04-01 13:52:14,896: OOooOoooOoOo = OOooo0O00o . run ( ) 2020-04-01 13:52:14,896: File "/opt/thinlinc/modules/thinlinc/wizard.py", line 102, in run 2020-04-01 13:52:14,896: return self . _run_gui ( ) 2020-04-01 13:52:14,896: File "/opt/thinlinc/modules/thinlinc/wizard.py", line 133, in _run_gui 2020-04-01 13:52:14,896: oOOO00o ( IIII ) 2020-04-01 13:52:14,896: File "/opt/thinlinc/modules/thinlinc/tlsetup/requirements.py", line 194, in <lambda> 2020-04-01 13:52:14,896: Ii1 , IIiiIiI1 , O00O0O0O0 ) 2020-04-01 13:52:14,896: File "/opt/thinlinc/modules/thinlinc/tlsetup/pkginsthelp.py", line 96, in generic_gui_installer 2020-04-01 13:52:14,896: IIIiI11ii = init ( ) 2020-04-01 13:52:14,896: File "/opt/thinlinc/modules/thinlinc/tlsetup/requirements.py", line 135, in III1ii1iII 2020-04-01 13:52:14,896: oo0oooooO0 = packageinstaller . create_backend ( ) 2020-04-01 13:52:14,896: File "/opt/thinlinc/modules/thinlinc/packageinstaller/__init__.py", line 31, in create_backend 2020-04-01 13:52:14,896: return globals ( ) [ OOo0oO0oooOoO ] . Backend ( ) ; 2020-04-01 13:52:14,896: File "/opt/thinlinc/modules/thinlinc/packageinstaller/aptbackend.py", line 89, in __init__ 2020-04-01 13:52:14,896: self . _cache = apt . Cache ( ) 2020-04-01 13:52:14,897: File "/usr/lib/python2.7/dist-packages/apt/cache.py", line 105, in __init__ 2020-04-01 13:52:14,897: self.open(progress) 2020-04-01 13:52:14,897: File "/usr/lib/python2.7/dist-packages/apt/cache.py", line 154, in open 2020-04-01 13:52:14,897: self._list.read_main_list() 2020-04-01 13:52:14,897: SystemError: E:Type '.' is not known on line 1 in source list /etc/apt/sources.list
Fixed now, tested on Ubuntu 20.04 with a dot added as the first character to '/etc/apt/sources.list'.
The code was modified to catch any type of error from the backend's constructors instead of the specific one raised by apt.cache.
I could reproduce this with 4.12.1 on Ubuntu 20.04. I also modified sources.list as described in comment #4, and I got a slightly different error message from the one described in comment #1. The error message I got was the following: >2021-05-06 07:00:28,256: Traceback (most recent call last): >2021-05-06 07:00:28,256: File "/opt/thinlinc/sbin/../libexec/tl-setup.py", line 308, in <module> >2021-05-06 07:00:28,256: Oo0O0OOOoo ( ) >2021-05-06 07:00:28,256: File "/opt/thinlinc/sbin/../libexec/tl-setup.py", line 265, in Oo0O0OOOoo >2021-05-06 07:00:28,256: OOooOoooOoOo = OOooo0O00o . run ( ) >2021-05-06 07:00:28,256: File "/opt/thinlinc/modules/thinlinc/wizard.py", line 100, in run >2021-05-06 07:00:28,256: return self . _run_text ( ) >2021-05-06 07:00:28,256: File "/opt/thinlinc/modules/thinlinc/wizard.py", line 118, in _run_text >2021-05-06 07:00:28,256: oOOO00o ( ) >2021-05-06 07:00:28,257: File "/opt/thinlinc/modules/thinlinc/tlsetup/requirements.py", line 190, in <lambda> >2021-05-06 07:00:28,257: i1I1ii1II1iII ) >2021-05-06 07:00:28,257: File "/opt/thinlinc/modules/thinlinc/tlsetup/pkginsthelp.py", line 71, in generic_text_installer >2021-05-06 07:00:28,257: IIIiI11ii = init ( ) >2021-05-06 07:00:28,257: File "/opt/thinlinc/modules/thinlinc/tlsetup/requirements.py", line 135, in III1ii1iII >2021-05-06 07:00:28,257: oo0oooooO0 = packageinstaller . create_backend ( ) >2021-05-06 07:00:28,257: File "/opt/thinlinc/modules/thinlinc/packageinstaller/__init__.py", line 31, in create_backend >2021-05-06 07:00:28,257: return globals ( ) [ OOo0oO0oooOoO ] . Backend ( ) ; >2021-05-06 07:00:28,257: File "/opt/thinlinc/modules/thinlinc/packageinstaller/aptbackend.py", line 89, in __init__ >2021-05-06 07:00:28,257: self . _cache = apt . Cache ( ) >2021-05-06 07:00:28,257: File "/usr/lib/python2.7/dist-packages/apt/cache.py", line 170, in __init__ >2021-05-06 07:00:28,257: self.open(progress) >2021-05-06 07:00:28,257: File "/usr/lib/python2.7/dist-packages/apt/cache.py", line 232, in open >2021-05-06 07:00:28,257: self._cache = apt_pkg.Cache(progress) >2021-05-06 07:00:28,257: Error: E:Malformed entry 1 in list file /etc/apt/sources.list (Suite), E:The list of sources could not be read This error is however catched and written in the tl-setup.log as intended. So this solution looks good!