Compile error Ubuntu 26.04

[vaskark]

I was wondering if someone could help me with these compile errors:

output.txt

Any help would be greatly appreciated. Apologies if this isn't the correct forum for this kind of help.

Ubuntu 26.04.1
Waybar (latest git)

[keithbowes]

It looks like spdlog bundles a version of fmt which has incompatible definitions to system fmt. It seems that the proper thing to do is to pass -DSPDLOG_FMT_EXTERNAL=ON to CMake when compiling spdlog so that it won't use the bundled fmt version. Removing include/spdlog/fmt/bundled/ before compiling couldn't hurt either.