If this belongs in upgrade warnings, I could learn how to put out a DE translation also.
Around 6 a.m. GMT on April 1 an "apt update" in tty1 failed. It is still failing system is paintitblack lxqt. It is not my main computer, just a test bed on bare metal. I have made no additions to my sources.list
apt update
Hit:1 http://packages.siduction.org/extra unstable InRelease
Hit:2 http://packages.siduction.org/fixes unstable InRelease
Get:3 http://debian.ec.as6453.net/debian unstable InRelease [196 kB]
Fetched 196 kB in 3s (57.7 kB/s)
Encountered a section with no Package: header
Problem with MergeList /var/lib/apt/lists/httpredir.debian.org_debian_dists_unstable_non-free_binary-amd64_Packages
The package lists or status file could not be parsed or opened.
Can't call method "policy" on an undefined value at /usr/bin/apt-show-versions line 56.
Reading package lists... Error!
E: Problem executing scripts APT::Update::Post-Invoke-Success 'test -x /usr/bin/apt-show-versions || exit 0 ; apt-show-versions -i'
E: Sub-process returned an error code
E: Encountered a section with no Package: header
E: Problem with MergeList /var/lib/apt/lists/httpredir.debian.org_debian_dists_unstable_non-free_binary-amd64_Packages
E: The package lists or status file could not be parsed or opened.
More "fun"
aptitude show apt
[ ERR] Reading package lists
E: Encountered a section with no Package: header
E: Problem with MergeList /var/lib/apt/lists/httpredir.debian.org_debian_dists_unstable_non-free_binary-amd64_Packages
E: The package lists or status file could not be parsed or opened.
[ ERR] Reading package lists
E: Encountered a section with no Package: header
E: Problem with MergeList /var/lib/apt/lists/httpredir.debian.org_debian_dists_unstable_non-free_binary-amd64_Packages
E: The package lists or status file could not be parsed or opened.
1. Quick and dirty thought I have not done apt-get autoclean or apt-get clean. I could try apt-get clean.
2. From 2011 someone with similar used
dpkg --clear-avail ## and another possibility with MergeList problems that is what I believe to be my best option is 3.
rm /var/lib/apt/lists/* --force ## also recommended in 2012 for Ubuntu and several other postings Debian and Ubuntu
Edited ##### thanks for the help in the forum.
"rm /var/lib/apt/lists/httpredir.debian.org_debian_dists_unstable_non-free_binary-amd64_Packages"
did not help, but did not hurt.
What did work was
"rmdir /var/lib/apt/lists/partial"