conanfile.py

from conans import ConanFile
import os

class ToolkitConan(ConanFile):
    name = "toolkit"
    version = "1.0"

    def package_info(self):
        self.env_info.CC = "echo"
        self.env_info.CFLAGS = "custom cflags"

test_package_conanfile.py

from conans import ConanFile
import os

class ToolkitTestConan(ConanFile):

    def build(self):
        self.run("env | grep -i CC")
        self.run("env | grep -i CFLAGS")

        cmdline = "%s %s" % ( os.environ["CC"],  os.environ["CFLAGS"])
        self.output.info("> %s" % cmdline)
        self.run(cmdline)?                                              

toolkit

[build_requires]
toolkit/1.0@rui/test