Hi maintainers,

I tried installing linuxdeploy-plugin-appimage on a fresh Ubuntu system, and the process was extremely cumbersome. Here is the step-by-step path I had to take:

1. Clone the plugin repository manually:

   git clone https://github.com/linuxdeploy/linuxdeploy-plugin-appimage.git
   cd linuxdeploy-plugin-appimage

2. Initialize submodules:

   git submodule update --init --recursive

3. Create a build directory (optional, but standard with CMake):

   mkdir build && cd build
   cmake ..

4. Attempted to build:

   make
   sudo make install

   This failed due to clang complaining about -static-libstdc++ and -static-libgcc being unused, triggered by -Werror.

5. Temporary fix: remove -Werror or suppress the unused argument warnings:

   cmake -DCMAKE_CXX_FLAGS="-O2 -Wno-error=unused-command-line-argument" ..
   make
   sudo make install

6. Finally, the plugin compiled and installed:

   /usr/local/bin/linuxdeploy-plugin-appimage

Observations / Pain Points:

• The need to clone this repository manually is confusing. Ideally, the main linuxdeploy repository should include this plugin as a submodule or provide a streamlined install process. Users should not have to hunt it down separately.
• The build breaks on Clang because of hardcoded GCC-specific flags combined with -Werror. Many users will have Clang installed by default on modern distros.
• Submodule initialization is not documented in the README; newcomers may be confused by the missing lib/args and other submodules.
• The cumulative effect of all the steps makes installation unnecessarily painful, especially compared to the old make/apt style many developers are familiar with.

Suggestions:

• Consider integrating the plugin directly into the main linuxdeploy repository or provide a single install script.
• Make CMakeLists.txt more compiler-agnostic, especially when using -static-libstdc++ and -static-libgcc.
• Provide clear instructions for submodule initialization and common Clang issues in the README.