internal/build: Consider running go mod download prior to build

[radeksimko]

We currently run just go build in order to build the tool after cloning (and installing appropriate Go version):

hc-install/internal/build/go_build.go

Lines 53 to 68 in 7852649

	goArgs := []string{"build", "-o", filepath.Join(targetDir, binaryName)}
	if gb.DetectVendoring {
	vendorDir := filepath.Join(repoDir, "vendor")
	if fi, err := os.Stat(vendorDir); err == nil && fi.IsDir() {
	goArgs = append(goArgs, "-mod", "vendor")
	}
	}
	gb.log().Printf("executing %s %q in %q", reqGo.Cmd, goArgs, repoDir)
	cmd := exec.CommandContext(ctx, reqGo.Cmd, goArgs...)
	cmd.Dir = repoDir
	out, err := cmd.CombinedOutput()
	if err != nil {
	return "", fmt.Errorf("unable to build: %w\n%s", err, out)
	}

There is a high likelihood that we would benefit from running go mod download to 1st download dependencies in a separate step. That would allow us to more clearly distinguish failures related to dependency/networking issues from actual build errors.

2023/01/10 03:15:32 go_build.go:62: executing go1.19.4 ["build" "-o" "/var/folders/24/8k48jl6d249_n_qfxwsl6xvm0000gn/T/hc-install-terraform-a086453783c74e0bf03ea23009d15d3af63e7415317297110/terraform"] in "/var/folders/24/8k48jl6d249_n_qfxwsl6xvm0000gn/T/hc-install-build-terraform2680510350"
panic: test timed out after 30m0s

goroutine 40 [running]:
testing.(*M).startAlarm.func1()
	/Users/runner/hostedtoolcache/go/1.17.13/x64/src/testing/testing.go:1788 +0x8e
created by time.goFunc
	/Users/runner/hostedtoolcache/go/1.17.13/x64/src/time/sleep.go:180 +0x31

goroutine 1 [chan receive, 29 minutes]:
testing.(*T).Run(0xc00012c820, {0x1404bcd, 0xa0c61c40cb}, 0x141d488)
	/Users/runner/hostedtoolcache/go/1.17.13/x64/src/testing/testing.go:1307 +0x375
testing.runTests.func1(0xc00013c930)
	/Users/runner/hostedtoolcache/go/1.17.13/x64/src/testing/testing.go:1598 +0x6e
testing.tRunner(0xc00012c820, 0xc000113d18)
	/Users/runner/hostedtoolcache/go/1.17.13/x64/src/testing/testing.go:1259 +0x[102](https://github.com/hashicorp/hc-install/actions/runs/3879804908/jobs/6617325038#step:4:103)
testing.runTests(0xc0000e4580, {0x16f89e0, 0x4, 0x4}, {0x[108](https://github.com/hashicorp/hc-install/actions/runs/3879804908/jobs/6617325038#step:4:109)294d, 0x13ff24d, 0x1700520})
	/Users/runner/hostedtoolcache/go/1.17.13/x64/src/testing/testing.go:1596 +0x43f
testing.(*M).Run(0xc0000e4580)
	/Users/runner/hostedtoolcache/go/1.17.13/x64/src/testing/testing.go:1504 +0x51d
main.main()
	_testmain.go:49 +0x14b

goroutine 19 [chan receive, 17 minutes]:
os/exec.(*Cmd).Wait(0xc01674c000)
	/Users/runner/hostedtoolcache/go/1.17.13/x64/src/os/exec/exec.go:518 +0x188
os/exec.(*Cmd).Run(0x4)
	/Users/runner/hostedtoolcache/go/1.17.13/x64/src/os/exec/exec.go:341 +0x39
os/exec.(*Cmd).CombinedOutput(0xc01674c000)
	/Users/runner/hostedtoolcache/go/1.17.13/x64/src/os/exec/exec.go:570 +0x96
github.com/hashicorp/hc-install/internal/build.(*GoBuild).Build(0x16f3ca0, {0x1486d08, 0xc01a1b4180}, {0xc00008f5c0, 0x2}, {0xc01a139180, 0x77}, {0x13fd28e, 0x9})
	/Users/runner/work/hc-install/hc-install/internal/build/go_build.go:65 +0x57b
github.com/hashicorp/hc-install/build.(*GitRevision).Build(0xc0000e4600, {0x1486cd0, 0xc0000a8008})
	/Users/runner/work/hc-install/hc-install/build/git_revision.go:171 +0xbab
github.com/hashicorp/hc-install/build.TestGitRevision_terraform(0xc00012c9c0)
	/Users/runner/work/hc-install/hc-install/build/git_revision_test.go:28 +0x1c5
testing.tRunner(0xc00012c9c0, 0x141d488)
	/Users/runner/hostedtoolcache/go/1.17.13/x64/src/testing/testing.go:1259 +0x102
created by testing.(*T).Run
	/Users/runner/hostedtoolcache/go/1.17.13/x64/src/testing/testing.go:1306 +0x35a

goroutine 11 [IO wait, 17 minutes]:
internal/poll.runtime_pollWait(0x6f3ddc8, 0x72)
	/Users/runner/hostedtoolcache/go/1.17.13/x64/src/runtime/netpoll.go:303 +0x85
internal/poll.(*pollDesc).wait(0xc01a1b4060, 0xc01885c242, 0x1)
	/Users/runner/hostedtoolcache/go/1.17.13/x64/src/internal/poll/fd_poll_runtime.go:84 +0x32
internal/poll.(*pollDesc).waitRead(...)
	/Users/runner/hostedtoolcache/go/1.17.13/x64/src/internal/poll/fd_poll_runtime.go:89
internal/poll.(*FD).Read(0xc01a1b4060, {0xc01885c242, 0x1bbe, 0x1bbe})
	/Users/runner/hostedtoolcache/go/1.17.13/x64/src/internal/poll/fd_unix.go:167 +0x25a
os.(*File).read(...)
	/Users/runner/hostedtoolcache/go/1.17.13/x64/src/os/file_posix.go:32
os.(*File).Read(0xc0186d2010, {0xc01885c242, 0x0, 0xc00b84fea0})
	/Users/runner/hostedtoolcache/go/1.17.13/x64/src/os/file.go:[119](https://github.com/hashicorp/hc-install/actions/runs/3879804908/jobs/6617325038#step:4:120) +0x5e
bytes.(*Buffer).ReadFrom(0xc0196b0[120](https://github.com/hashicorp/hc-install/actions/runs/3879804908/jobs/6617325038#step:4:121), {0x[147](https://github.com/hashicorp/hc-install/actions/runs/3879804908/jobs/6617325038#step:4:148)d180, 0xc0186d2010})
	/Users/runner/hostedtoolcache/go/1.17.13/x64/src/bytes/buffer.go:204 +0x98
io.copyBuffer({0x147c680, 0xc0196b0120}, {0x147d180, 0xc0186d2010}, {0x0, 0x0, 0x0})
	/Users/runner/hostedtoolcache/go/1.17.13/x64/src/io/io.go:409 +0x14b
io.Copy(...)
	/Users/runner/hostedtoolcache/go/1.17.13/x64/src/io/io.go:382
os/exec.(*Cmd).writerDescriptor.func1()
	/Users/runner/hostedtoolcache/go/1.17.13/x64/src/os/exec/exec.go:311 +0x3a
os/exec.(*Cmd).Start.func1(0x0)
	/Users/runner/hostedtoolcache/go/1.17.13/x64/src/os/exec/exec.go:444 +0x25
created by os/exec.(*Cmd).Start
	/Users/runner/hostedtoolcache/go/1.17.13/x64/src/os/exec/exec.go:443 +0x87b
FAIL	github.com/hashicorp/hc-install/build	1802.321s