Specifying the platform will generate duplicate dependencies.

[nacljht]

-- mylib.cc --
#include "external.h"

#ifdef EXTERNAL2_H
#include "external2.h"
#endif

-- BUILD --
# gazelle:cc_group unit
# gazelle:cc_platform linux x86_64 //:on_linux_x86_64
# gazelle:cc_indexfile external.ccindex

-- external.ccindex --
{
    "external.h": "@external//:external",
    "external2.h": "@external//:external"
}

it will generate duplicate dependencies (@external)

load("@rules_cc//cc:defs.bzl", "cc_library")

cc_library(
    name = "mylib",
    srcs = ["mylib.cc"],
    implementation_deps = [
        "@external",
    ] + select({
        "//conditions:default": ["@external"],
    }),
    visibility = ["//visibility:public"],
)

I think since EXTERNAL2_H is not defined, the #include "external2.h" directive is conditionally disabled and treated by Gazelle as a constrained dependency, while the unconditional #include "external.h" is treated as a generic dependency. Because both headers map to the same Bazel target (@external//:external) in external.ccindex, this results in duplicate entries for that target

[jayconrod]

Reproduced with v0.4.0.

@mateusz-olczyk could you take a look at this one?

[mateusz-olczyk]

Reproduced with v0.4.0.

@mateusz-olczyk could you take a look at this one?

Yes, I'll take a look as soon as I have finished #159