Native environment linker problems after upgrading to 5.0.1

[wrong-kendall]

Configuration

Operating system:
DISTRIB_ID=LinuxMint
DISTRIB_RELEASE=19.1
DISTRIB_CODENAME=tessa
DISTRIB_DESCRIPTION="Linux Mint 19.1 Tessa"

PlatformIO Version (platformio --version):
PlatformIO, version 5.0.1

Description of problem

When trying to run a test file that previously worked on 4.3.4, the linker fails to link. I specifically noticed this while using ArduinoFake but suspect it happens in other cases too (but haven't verified). I used the test case below and 2 separate virtualenvs to verify that the test runs on 4.3.4 but not on 5.0.1

Steps to Reproduce

1. Create header that conditionally includes ArduinoFake.h
2. Make a class with a simple method that calls one of the Arduino builtin functions
3. Create a test that includes ArduinoFake.h, instantiates the class created in step 2 and tries to call that method.

Actual Results

Verbose mode can be enabled via `-v, --verbose` option
Collected 1 items

Processing * in native environment
-------------------------------------------------------------------------------------------------------------------------------------------------------------
Building...
.pio/build/native/lib1de/libFoo.a(Foo.o): In function `Foo::DoStuff()':
Foo.cpp:(.text+0x17): undefined reference to `pinMode'
collect2: error: ld returned 1 exit status
*** [.pio/build/native/program] Error 1
================================================================ [FAILED] Took 2.18 seconds ================================================================

Test    Environment    Status    Duration
------  -------------  --------  ------------
*       m4             IGNORED
*       native         FAILED    00:00:02.184
=========================================================== 1 failed, 0 succeeded in 00:00:02.184 ===========================================================

Expected Results

Verbose mode can be enabled via `-v, --verbose` option
Collected 1 items

Processing * in native environment
---------------------------------------------------------------------------------------------------------
Building...
CorePackageManager: Installing tool-scons @ ~3.30102.0
tool-scons @ 3.30102.0 has been successfully installed!
Uninstalling tool-scons @ 4.40001.0: 	[OK]
Testing...
test/test_main.cpp:20:test_truth	[PASSED]

-----------------------
1 Tests 0 Failures 0 Ignored
OK
====================================== [PASSED] Took 3.26 seconds ======================================

Test    Environment    Status    Duration
------  -------------  --------  ------------
*       m4             IGNORED
*       native         PASSED    00:00:03.265
====================================== 1 succeeded in 00:00:03.265 ======================================

If problems with PlatformIO Build System:

The content of platformio.ini:

[env:m4]
platform = atmelsam
board = adafruit_feather_m4
framework = arduino

[env:native]
platform = native
build_flags = -std=gnu++11
lib_deps =
    ArduinoFake
lib_compat_mode = off

Source file to reproduce issue:
Foo.h

#pragma once
#ifdef UNIT_TEST
#include "ArduinoFake.h"
#else
#include "Arduino.h"
#endif

class Foo {
public:
  Foo(){};
  void DoStuff();
};

Foo.cpp

#include "Foo.h"

void Foo::DoStuff() {
    pinMode(1, HIGH);
    return;
}

test_main.cpp

#include <ArduinoFake.h>
#include <unity.h>

using namespace fakeit;

#include "Foo.h"

void setUp(void) { ArduinoFakeReset(); }

void test_kaboom() {
  Foo f;
  f.DoStuff();
}

void test_truth() { TEST_ASSERT_TRUE(true); }
int main(int argc, char **argv) {
  UNITY_BEGIN();
  RUN_TEST(test_truth);
  return UNITY_END();
}

Additional info

Here are the verbose runs for each.
linker_verbose_failure.txt
linker_verbose_success.txt

[ivankravets]

Please re-test with the latest PIO Core dev version via pio upgrade --dev.

[wrong-kendall]

Confirmed success. Thanks!
[11:12:22 09/17/20]: <~/development/src/linker_woes>$ pio test -e native
Verbose mode can be enabled via -v, --verbose option
Collected 1 items

Processing * in native environment

Building...
Testing...
test/test_main.cpp:20:test_truth [PASSED]

---

1 Tests 0 Failures 0 Ignored
OK
============================================================================ [PASSED] Took 0.33 seconds ============================================================================

Test Environment Status Duration

---

•   m4             IGNORED
  

•   native         PASSED    00:00:00.331
  

============================================================================ 1 succeeded in 00:00:00.331 ============================================================================