After installing 3.9.7 with pyenv, during use
This problem was encountered when installing psycopg2.
Re-execution found no effect.
System python3 import without error
The python3.9.7 installed by pyenv reports an error
After checking the information, you need to install libffi-dev. The ubuntu installation command is as follows:
sudo apt-get install libffi-dev
Installation error: Unable to locate package libffi-dev
sudo apt-get install libffi-dev Reading package lists... Done Building dependency tree Reading state information... Done E: Unable to locate package libffi-dev
Find the problem, you need to modify the source, refer to the address.
https://super-unix.com/ubuntu/ubuntu-unable-to-locate-package-libffi-dev/
https://askubuntu.com/questions/626138/unable-to-locate-package-libffi-dev
After using the above method to simply add the source, it still reports an error: Ubuntu sudo apt get update 404 Not Found problem
Similarly, the example is as follows:
Err:14 http://old-releases.ubuntu.com/ubuntu focal Release 404 Not Found [IP: 91.189.88.247 80] Err:15 http://ppa.launchpad.net/team-gcc-arm-embedded/ppa/ubuntu focal Release 404 Not Found [IP: 91.189.95.85 80] Err:16 http://old-releases.ubuntu.com/ubuntu focal-updates Release 404 Not Found [IP: 91.189.88.247 80] Hit:17 https://linux-clients.seafile.com/seafile-deb/focal stable InRelease Err:18 http://old-releases.ubuntu.com/ubuntu focal-backports Release 404 Not Found [IP: 91.189.88.247 80] Err:19 http://old-releases.ubuntu.com/ubuntu focal-security Release 404 Not Found [IP: 91.189.88.247 80] Ign:13 https://launchpad.net/~terry.guo/ +archive/gcc-arm-embedded focal InRelease Err:20 https://launchpad.net/~terry.guo/ + archive/gcc-arm-embedded focal Release 404 Not Found [IP: 91.189.89.222 443]
Refer to the answer:
20.04 – Ubuntu sudo apt get update 404 Not Found problem – Ask Ubuntuj?j
Restore sources.list to default
deb http://archive.ubuntu.com/ubuntu/ focal main restricted universe multiverse #deb-src http://archive.ubuntu.com/ubuntu/ focal main restricted universe multiverse deb http://archive.ubuntu.com/ubuntu/ focal-updates main restricted universe multiverse #deb-src http://archive.ubuntu.com/ubuntu/ focal-updates main restricted universe multiverse deb http://archive.ubuntu.com/ubuntu/ focal-security main restricted universe multiverse #deb-src http://archive.ubuntu.com/ubuntu/ focal-security main restricted universe multiverse deb http://archive.ubuntu.com/ubuntu/ focal-backports main restricted universe multiverse #deb-src http://archive.ubuntu.com/ubuntu/ focal-backports main restricted universe multiverse deb http://archive.canonical.com/ubuntu focal partner #deb-src http://archive.canonical.com/ubuntu focal partner
Just re-apt-get update
sudo apt-get update
After apt-get is updated
sudo apt-get install libffi-dev sudo apt-get install libpq-dev python3-dev
After successful installation
pyenv install 3.9.7
Test successful