patchwork:tldr:8113f
The command patchwork is a tool or program that is being executed.
The -T option is used to specify the input image format, in this case, it expects a PNG file. ${png} is probably a placeholder that should be replaced with the actual filename or path of the PNG file.
The -O option is used to specify the output format or type. ${path-to-input-gv} is another placeholder that needs to be replaced with the actual path or filename for the input file, which is expected to be a Graphviz file (a popular graph visualization tool).
So, in summary, the command is telling the patchwork tool to read a PNG image file (${png}) and an input file in Graphviz format (${path-to-input-gv}), perform some actions or transformations, and generate output based on the provided options.