python program run via bazel unable to see stlink_cli.exe installed on host

[Uma Patil]

Hi,

I have python program that uses STLink_CI.EXE installed on my host machine. I have created custom rule to run py_binary. 

Custom rule:

load('//tools/flash:rules.bzl', 'flash_tool')

flash_tool(

    name = "run",

    device_type="stm32",

    srcs = ":cc_binary",

    visibility = ["//visibility:public"],

)

rules.bzl:

def _impl(ctx):

    args= ctx.actions.args()

    args.add(ctx.attr.device_type)

    ........

    ctx.actions.run(

        inputs = [ctx.file.srcs],

        arguments = [args],

        outputs = [ctx.outputs.text],

        executable = ctx.executable.runner)

flash_tool = rule(

    implementation = _impl,

    attrs = {

        "runner": attr.label(

            executable = True,

            cfg = "host",

            default=Label("//tools/flash")),

        "device_type":attr.string(mandatory = True),

        "srcs":attr.label(mandatory = True, allow_single_file = True,),

    },

    outputs = {

        "text": "%{name}.txt"},

)

When I run 

bazel build //examples/application:run --platforms=//stm32f4

It throws me error as STLInk_cli.exe is missing. How can i make custom rule to run on host so that it identifies the stlink_cli.exe? Or am I understanding it differently and  missing something different?

Please guide me on this.