Cannot install or upgrade any software in Ubuntu in Termux

[ThomasHeinrichSchmidt]

I have successfully followed your installation steps of ubuntu-in-termux on a Nexus 10 tablet running Android 5.1.1. using Termux 0.118.0+3b5018b from a termux-app_v0.118.0+3b5018b-apt-android-5-github-debug_armeabi-v7a.apk.
The last steps were

$ ./ubuntu.sh -y
$ ./startubuntu.sh
root@localhost:~# su     
root@localhost:~# apt-get update

But when I tried to upgrade packages I encountered a fatal error

root@localhost:~# apt-get upgrade -y
    ...
    dpkg: unrecoverable fatal error, aborting:
    unable to open directory '/var/lib/dpkg/updates/': Operation not permittted
    ...

But the directory in question does actually exist and is also accessible (I can cd into it and ls the contents).
Also, any other package installation either fails with the same message or E: Unable to locate package python for something like root@localhost:~# apt-get install python. Latter is probably due to upgrade not being succsessful.
What do you think? Any chance for me to clean this up?

[ThomasHeinrichSchmidt]

@sonukaloshiya: Does that mean you did successfully follow the installation steps of ubuntu-in-termux on a Nexus 10 tablet running Android 5.1.1.? And afterwards you were able to successfully apt-get upgrade -y? Really?

[ThomasHeinrichSchmidt]

What do you want to tell me?

[MFDGaming]

From what I know, the legacy android termux repos where taken down

[ThomasHeinrichSchmidt]

Sad, but now I know why installs fail.