reverse build/host activation order, to give build exe's higher priority

conda_build/build.py

@@ -842,6 +842,25 @@ def bundle_conda(output, metadata, env, stats, **kw):
  else:
  if not metadata.always_include_files():
  log.warn("No files or script found for output {}".format(output.get('name')))
+ build_deps = metadata.get_value('requirements/build')
+ host_deps = metadata.get_value('requirements/host')
+ build_pkgs = [pkg.split()[0] for pkg in build_deps]
+ host_pkgs = [pkg.split()[0] for pkg in host_deps]
+ dangerous_double_deps = {'python': 'PYTHON', 'r-base': 'R'}
+ for dep, env_var in dangerous_double_deps.items():
+ if all(dep in pkgs_list for pkgs_list in (build_pkgs, host_pkgs)):
+ raise CondaBuildException("Empty package; {0} present in build and host deps. "
+ "You probably picked up the build environment's {0} "
+ " executable. You need to alter your recipe to "
+ " use the {1} env var in your recipe to "
+ "run that executable.".format(dep, env_var))
+ elif (dep in build_pkgs and metadata.uses_new_style_compiler_activation):
+ link = ("https://conda.io/docs/user-guide/tasks/build-packages/"
+ "define-metadata.html#host")
+ raise CondaBuildException("Empty package; {0} dep present in build but not "
+ "host requirements. You need to move your {0} dep "
+ "to the host requirements section. See {1} for more "
+ "info." .format(dep, link))
  initial_files = set(utils.prefix_files(metadata.config.host_prefix))
 
  for pat in metadata.always_include_files():
@@ -986,18 +1005,6 @@ def _write_sh_activation_text(file_handle, m):
  activate_path = ''.join((cygpath_prefix,
  os.path.join(utils.root_script_dir, 'activate').replace('\\', '\\\\'),
  cygpath_suffix))
- build_prefix_path = ''.join((cygpath_prefix,
- m.config.build_prefix.replace('\\', '\\\\'),
- cygpath_suffix))
-
- file_handle.write('source "{0}" "{1}"\n'.format(activate_path, build_prefix_path))
-
- # conda 4.4 requires a conda-meta/history file for a valid conda prefix
- history_file = join(m.config.build_prefix, 'conda-meta', 'history')
- if not isfile(history_file):
- if not isdir(dirname(history_file)):
- os.makedirs(dirname(history_file))
- open(history_file, 'a').close()
 
  if m.is_cross:
  # HACK: we need both build and host envs "active" - i.e. on PATH,
@@ -1019,12 +1026,26 @@ def _write_sh_activation_text(file_handle, m):
  if not isdir(dirname(history_file)):
  os.makedirs(dirname(history_file))
  open(history_file, 'a').close()
- file_handle.write('unset CONDA_PATH_BACKUP\n')
- file_handle.write('export CONDA_MAX_SHLVL=2\n')
  host_prefix_path = ''.join((cygpath_prefix,
  m.config.host_prefix.replace('\\', '\\\\'),
  cygpath_suffix))
  file_handle.write('source "{0}" "{1}"\n' .format(activate_path, host_prefix_path))
+ file_handle.write('unset CONDA_PATH_BACKUP\n')
+ file_handle.write('export CONDA_MAX_SHLVL=2\n')
+
+ # Write build prefix activation AFTER host prefix, so that its executables come first
+ build_prefix_path = ''.join((cygpath_prefix,
+ m.config.build_prefix.replace('\\', '\\\\'),
+ cygpath_suffix))
+
+ file_handle.write('source "{0}" "{1}"\n'.format(activate_path, build_prefix_path))
+
+ # conda 4.4 requires a conda-meta/history file for a valid conda prefix
+ history_file = join(m.config.build_prefix, 'conda-meta', 'history')
+ if not isfile(history_file):
+ if not isdir(dirname(history_file)):
+ os.makedirs(dirname(history_file))
+ open(history_file, 'a').close()
 
 
 def _write_activation_text(script_path, m):

conda_build/windows.py

@@ -202,9 +202,6 @@ def build_vcvarsall_cmd(cmd, arch=arch_selector):
 
 
 def _write_bat_activation_text(file_handle, m):
- file_handle.write('call "{conda_root}\\activate.bat" "{prefix}"\n'.format(
- conda_root=root_script_dir,
- prefix=m.config.build_prefix))
  if m.is_cross:
  # HACK: we need both build and host envs "active" - i.e. on PATH,
  # and with their activate.d scripts sourced. Conda only
@@ -225,12 +222,16 @@ def _write_bat_activation_text(file_handle, m):
  if not isdir(dirname(history_file)):
  os.makedirs(dirname(history_file))
  open(history_file, 'a').close()
- # removing this placeholder should make conda double-activate with conda 4.3
- file_handle.write('set "PATH=%PATH:CONDA_PATH_PLACEHOLDER;=%"\n')
- file_handle.write('set CONDA_MAX_SHLVL=2\n')
  file_handle.write('call "{conda_root}\\activate.bat" "{prefix}"\n'.format(
  conda_root=root_script_dir,
  prefix=m.config.host_prefix))
+ # removing this placeholder should make conda double-activate with conda 4.3
+ file_handle.write('set "PATH=%PATH:CONDA_PATH_PLACEHOLDER;=%"\n')
+ file_handle.write('set CONDA_MAX_SHLVL=2\n')
+ # Write build prefix activation AFTER host prefix, so that its executables come first
+ file_handle.write('call "{conda_root}\\activate.bat" "{prefix}"\n'.format(
+ conda_root=root_script_dir,
+ prefix=m.config.build_prefix))
 
 
 def build(m, bld_bat):

tests/test-recipes/metadata/_compiler_python_build_section/meta.yaml

@@ -0,0 +1,13 @@
+# common point of confusion around the split between build and host
+
+package:
+ name: empty_pkg_with_python_build_host
+ version: 1.0
+
+build:
+ script: echo weeee
+
+requirements:
+ build:
+ - {{ compiler('c') }}
+ - python

tests/test-recipes/metadata/_empty_pkg_with_python_build_host/meta.yaml

@@ -0,0 +1,12 @@
+package:
+ name: empty_pkg_with_python_build_host
+ version: 1.0
+
+build:
+ script: echo weeee
+
+requirements:
+ build:
+ - python
+ host:
+ - python

tests/test_api_build.py

@@ -32,7 +32,7 @@
 from conda_build.utils import (copy_into, on_win, check_call_env, convert_path_for_cygwin_or_msys2,
  package_has_file, check_output_env, get_conda_operation_locks, rm_rf)
 from conda_build.os_utils.external import find_executable
-from conda_build.exceptions import DependencyNeedsBuildingError
+from conda_build.exceptions import DependencyNeedsBuildingError, CondaBuildException
 
 from .utils import is_valid_dir, metadata_dir, fail_dir, add_mangling, FileNotFoundError
 
@@ -1224,3 +1224,15 @@ def test_overlinking_detection(testing_config):
  with pytest.raises(SystemExit):
  api.build(recipe, config=testing_config)
  rm_rf(dest_file)
+
+
+def test_empty_package_with_python_in_build_and_host_barfs(testing_config):
+ recipe = os.path.join(metadata_dir, '_empty_pkg_with_python_build_host')
+ with pytest.raises(CondaBuildException):
+ api.build(recipe, config=testing_config)
+
+
+def test_empty_package_with_python_and_compiler_in_build_barfs(testing_config):
+ recipe = os.path.join(metadata_dir, '_compiler_python_build_section')
+ with pytest.raises(CondaBuildException):
+ api.build(recipe, config=testing_config)