Make with protobuf

[julien-ft]

Hi,

First of all, thank you for your work !

I have a problem when I try to make with protobuf :

[24%] Built target dot_dep
src/transitmap/output/protobuf/CMakeFiles/proto.dir/build.make:73: *** target pattern contains no '%'.  Stop.
make[1]: *** [CMakeFiles/Makefile2:668: src/transitmap/output/protobuf/CMakeFiles/proto.dir/all] Error 2
make: *** [Makefile:146: all] Error 2

This is the problematic line (line 73) :

src/transitmap/output/protobuf/vector_tile.pb.h: src/transitmap/output/protobuf/protobuf::protoc

When I remove protobuf packages and do again the cmake + make, it's works, i can generate json and svg

I work on Ubuntu 22.04.4 LTS

Thank you !

[pcace]

had the same problem - i fixed it by installing the protobuf-compiler package too.
maybe it would be nice to add this to the required packages in the readme?
sudo apt install libprotobuf-dev protobuf-compiler

[tylershuster]

Same issue on macOS 26.0.1. Ran brew unlink protobuf and it made fine

[tylershuster]

Unfortunately this now means that I cannot make tiles 🤷

[patrickbr]

I finally found the time to investigate this issue, sorry for the delay here.

I can indeed reproduce the issue if libprotobuf-dev is installed, but protobuf-compiler is not. protobuf-compiler is required to generate the C++ header files from the vector_tile.proto file. One possibility to completely avoid the protobuf-compiler dependency would be to include the generated vector.tile.pb.h file in this repo, but I don't think that this is a good idea, as future versions of libprotobuf-dev might be incompatible with an outdated header file.

I will instead list the optional dependency in the README, and will change the Makefile so that the build will not break if protobuf-compiler is missing.

[patrickbr]

Should be fixed with #34.