Construction Environments¶

The PlatformIO Build System uses two built-in construction environments to process each project:

env, Import("env") - the global construction environment used for the Development Platforms and Frameworks build scripts, upload tools, Library Dependency Finder (LDF), and other internal operations
projenv, Import("projenv") - the isolated construction environment used for processing the project source code in src_dir. Please note that any src_build_flags specified in “platformio.ini” (Project Configuration File) will be passed to projenv and not to env.

Warning

projenv is available only for POST-type scripts
Flags passed to env using PRE-type script will affect projenv too.

my_pre_extra_script.py:

Import("env")

# access to global construction environment
print(env)

# Dump construction environment (for debug purpose)
print(env.Dump())

# append extra flags to global build environment
# which later will be used to build:
# - project source code
# - frameworks
# - dependent libraries
env.Append(CPPDEFINES=[
  "MACRO_1_NAME",
  ("MACRO_2_NAME", "MACRO_2_VALUE")
])

my_post_extra_script.py:

Import("env", "projenv")

# access to global construction environment
print(env)

# access to project construction environment
print(projenv)

# Dump construction environments (for debug purpose)
print(env.Dump())
print(projenv.Dump())

# append extra flags to global build environment
# which later will be used to build:
# - frameworks
# - dependent libraries
env.Append(CPPDEFINES=[
  "MACRO_1_NAME",
  ("MACRO_2_NAME", "MACRO_2_VALUE")
])

# append extra flags to only project build environment
projenv.Append(CPPDEFINES=[
  "PROJECT_EXTRA_MACRO_1_NAME",
  ("ROJECT_EXTRA_MACRO_2_NAME", "ROJECT_EXTRA_MACRO_2_VALUE")
])

See examples below how to import construction environments and modify existing data or add new.