Add message for older python version (#2470)

* readme.md: fix guide for ubuntu20.04

* setup.sh: add message for unsupported python version

README.md

@@ -49,7 +49,11 @@ nix shell github:pwndbg/pwndbg
 pwndbg ./your-binary
 ```
 
-Pwndbg is supported on Ubuntu 22.04, and 24.04 with GDB 12.1 and later. We do not test on any older versions of Ubuntu, so `pwndbg` may not work on these versions (for Ubuntu 18.04 use the [2023.07.17: ubuntu18.04-final release](https://github.com/pwndbg/pwndbg/releases/tag/2023.07.17)). We may accept pull requests fixing issues in older versions on a case by case basis, please discuss this with us on [Discord](https://discord.gg/x47DssnGwm) first. You can also always checkout an older version of `pwndbg` from around the time the Ubuntu version you're interested in was still supported by Canonical, or you can attempt to build a newer version of GDB from source.
+Pwndbg is supported on Ubuntu 22.04, and 24.04 with GDB 12.1 and later. We do not test on any older versions of Ubuntu, so `pwndbg` may not work on these versions.
+- For Ubuntu 20.04 use the [2024.08.29 release](https://github.com/pwndbg/pwndbg/releases/tag/2024.08.29)
+- For Ubuntu 18.04 use the [2023.07.17: ubuntu18.04-final release](https://github.com/pwndbg/pwndbg/releases/tag/2023.07.17)
+
+We may accept pull requests fixing issues in older versions on a case by case basis, please discuss this with us on [Discord](https://discord.gg/x47DssnGwm) first. You can also always checkout an older version of `pwndbg` from around the time the Ubuntu version you're interested in was still supported by Canonical, or you can attempt to build a newer version of GDB from source.
 
 Other Linux distributions are also supported via `setup.sh`, including:
 

setup.sh

@@ -152,11 +152,6 @@ if linux; then
             ;;
         "gentoo")
             install_emerge
-            if ! hash sudo 2> /dev/null && whoami | grep root; then
-                sudo() {
-                    ${*}
-                }
-            fi
             ;;
         "freebsd")
             install_freebsd
@@ -193,6 +188,15 @@ if ! osx; then
     PYTHON+="${PYVER}"
 fi
 
+# Check python version supported: <3.10, 3.99>
+is_supported=$(echo "$PYVER" | grep -E '3\.(10|11|12|13|14|15|16|17|18|19|[2-9][0-9])' || true)
+if [[ -z "$is_supported" ]]; then
+    echo "Your system has unsupported python version. Please use older pwndbg release:"
+    echo "'git checkout 2024.08.29' - python3.8, python3.9"
+    echo "'git checkout 2023.07.17' - python3.6, python3.7"
+    exit
+fi
+
 # Install Poetry
 if ! command -v poetry &> /dev/null; then
     echo "Poetry not found. Installing Poetry..."