The package of libfetch library is now available.
Well, it hasn't been tested due to a lack of network connection between ARAnyM and my PC, but it is present and registered in the system.
As a reminder, the bug was as follows:
The tsort command failed because of an odd number of arguments (an even number is required for the program to create pairs).
The solution is to go to the directory where the build is taking place, run the command manually without using tsort to generate the library...
...and finally return to the original directory to run bmake again and complete the build.