Ubuntu 20.04安装Xilinx Petalinux遇Python版本及依赖报错求助

I’ve run into this exact issue before with Ubuntu 20.04—since it doesn’t ship with a default python symlink pointing to Python 2.7, Petalinux can’t detect the required version even if you’ve installed Python 2.7 already. Here’s how to resolve it step by step:

Step 1: Install Python 2.7 and its dependencies #

First, make sure Python 2.7 is properly installed along with development tools:

sudo apt update
sudo apt install python2.7 python2.7-dev

Step 2: Set up pip2 (optional but useful) #

If you need pip for Python 2.7 to manage additional dependencies, install it using the legacy bootstrap script:

curl https://bootstrap.pypa.io/pip/2.7/get-pip.py --output get-pip.py
sudo python2.7 get-pip.py

Step 3: Link python command to Python 2.7 #

Ubuntu 20.04 uses python3 as the default, so we need to explicitly map the python command to Python 2.7 using update-alternatives (this is cleaner than manual symlinks):

# Add Python 2.7 to the alternatives list
sudo update-alternatives --install /usr/bin/python python /usr/bin/python2.7 1
# Add Python 3 (default) to the list (lets you switch back later if needed)
sudo update-alternatives --install /usr/bin/python python /usr/bin/python3.8 2

Then run this command to select Python 2.7 as the default:

sudo update-alternatives --config python

You’ll see a prompt similar to this—just enter the number corresponding to Python 2.7:

There are 2 choices for the alternative python (providing /usr/bin/python).

Selection Path Priority Status #

• 0 /usr/bin/python3.8 2 auto mode
  1 /usr/bin/python2.7 1 manual mode

Press to keep the current choice[*], or type selection number: 1

Step 4: Verify the Python version #

Check that the python command now points to the correct version:

python --version

You should see output like Python 2.7.18 (or a similar patch version).

Step 5: Install all required Petalinux dependencies #

Don’t forget to install the full set of packages Petalinux needs to avoid other installation errors:

sudo apt install build-essential git make net-tools libncurses5-dev tftpd zlib1g-dev libssl-dev flex bison libselinux1 gnupg wget diffstat chrpath socat xterm autoconf libtool tar unzip texinfo zlib1g-dev gcc-multilib automake zlib1g:i386 screen pax gawk python3-pip python3-pexpect xz-utils debianutils iputils-ping python3-git python3-jinja2 libegl1-mesa libsdl1.2-dev pylint3 cpio

After completing these steps, your Petalinux installation should recognize the Python 2.7 version and proceed without the error you encountered.

内容的提问来源于stack exchange，提问作者Arman Zhumakhan