Previously the Go toolchain had no explicit support for "tools" and so we
used the typical Go community workaround of adding "tools.go" files (two,
for some reason) that existed only to trick the Go toolchain into
considering the tools as dependencies we could track in go.mod.
Go 1.24 introduced explicit support for tracking tools as part of go.mod,
and the ability to run those using "go tool" instead of "go run", and so
this commit switches us over to using that strategy for everything we were
previously managing in tools.go.
There are some intentional exceptions here:
- The protobuf-compile script can't use "go tool" or "go run" because the
tools in question are run only indirectly through protoc. However, we
do still use the "tool" directive in go.mod to tell the Go toolchain that
we depend on those tools, so that it'll track which versions we are
currently using as part of go.mod.
- Our golangci-lint Makefile target uses "go run" to run a specific
version of golangci-lint. We _intentionally_ don't consider that tool
to be a direct dependency of OpenTofu because it has a lot of indirect
dependencies that would pollute our go.mod file. Therefore that continues
to use "go run" after this commit.
- Both of our tools.go files previously referred to
github.com/nishanths/exhaustive , but nothing actually appears to be
using that tool in the current OpenTofu tree, so it's no longer a
dependency after this commit.
All of the dependencies we have _only_ for tools are now classified as
"indirect" in the go.mod file. This is the default behavior of the Go
toolchain and appears to be motivated by making it clearer that these
modules do not contribute anything to the runtime behavior of OpenTofu.
This also corrected a historical oddity in our go.mod where for some reason
the "indirect" dependencies had been split across two different "require"
directives; they are now all grouped together in a single directive.
Signed-off-by: Martin Atkins <mart@degeneration.co.uk>