The way we create the kubo binary for coverage is very hacky.
It uses the testing tool. In order to simulate a Kubo binary,
we need to supress all the output that would otherwise be printed
by 'go test'.
So far, we were setting os.Stdout and os.Stderr as a read-only
/dev/null file descriptor. This is causing issues with the new
versions of Go:
error generating coverage report: write /dev/null: bad file descriptor
exit status 2
Updating it to a Read-Write file descriptor solves the problem.
I did not try looking into what is causing this issue now. There have
been some updates to the 'go test' tool in Go 1.20 and it is likely
that some error is now being checked for that hasn't been checked
before. Writing to a read-only file descriptor always failed. But
the error was just supressed somehow.
This commit introduces non-recursive Makefile infrastructure that replaces current Makefile infrastructure.
It also generally cleanups the Makefiles, separates them into nicer sub-modules and centralizes common operations into single definitions.
It allows to depend on any target that is defined in the makefile, this means that for example `gx install` is called once when `make build test_expensive_sharness` is called instead of 4 or 5 times.
It also makes the dependencies much cleaner and allows for reuse of modules. For example sharness coverage collection (WIP) uses sharness target with amended PATH, previously it might have been possible but not without wiring in the coverage collection into sharness make runner code.
Yes, it is more complex but not much more. There are few rules that have to be followed and few complexities added but IMHO it is worth it.
How to NR-make:
1. If make is to generate some file via a target, it MUST be defined in Rules.mk file in the directory of the target.
2. `Rules.mk` file MUST have `include mk/header.mk` statement as the first line and `include mk/footer.mk` statement as the last line (apart from project root `Rules.mk`).
3. It then MUST be included by the closest `Rules.mk` file up the directory tree.
4. Inside a `Rules.mk` special variable accessed as `$(d)` is defined. Its value is current directory, use it so if the `Rules.mk` file is moved in the tree it still works without a problem. Caution: this variable is not available in the recipe part and MUST NOT be used. Use name of the target or prerequisite to extract it if you need it.
5. Make has only one global scope, this means that name conflicts are a thing. Names SHOULD follow `VAR_NAME_$(d)` convention. There are exceptions from this rule in form of well defined global variables. Examples: General lists `TGT_BIN`, `CLEAN`; General targets: `TEST`, `COVERAGE`; General variables: `GOFLAGS`, `DEPS_GO`.
3. Any rules, definitions or variables that fit some family SHOULD be defined in `mk/$family.mk` file and included from project root `Rules.mk`
License: MIT
Signed-off-by: Jakub Sztandera <kubuxu@protonmail.ch>
