Simple example that attempts to use gazelle with multiple src/ repositories.

How to check that the go flow is fine:

$ export GOPATH=$PWD
$ go install repo.4/cmd/cmd4
$ ./bin/cmd4
pkg1
pkg2
pkg3
pkg4
$

The broken bazel flow:

$ cd src
$ bazel run //:gazelle

The issue is some of the deps from repo.4/cmd/cmd4/BUILD incorrectly point to //vendor/.

The resulting go_default_library target:

go_library(
    name = "go_default_library",
    srcs = ["main.go"],
    importpath = "repo.4/cmd/cmd4",
    visibility = ["//visibility:private"],
    deps = [
        "//vendor/repo.1/pkg1:go_default_library",
        "//vendor/repo.2/pkg2:go_default_library",
        "//vendor/repo.3/pkg3:go_default_library",
        "//vendor/repo.4/pkg4:go_default_library",
    ],
)

The expected go_default_library target:

go_library(
    name = "go_default_library",
    srcs = ["main.go"],
    importpath = "repo.4/cmd/cmd4",
    visibility = ["//visibility:private"],
    deps = [
        "//vendor/repo.1/pkg1:go_default_library",
        "//vendor/repo.2/pkg2:go_default_library",
        "//repo.3/pkg3:go_default_library",
        "//repo.4/pkg4:go_default_library",
    ],
)