check requirements.txt  for local references
allows assemble_from_subset when requirements.txt doesn't contain any local references
MODIFY
repo2docker/buildpacks/python/__init__.py
repo2docker/buildpacks/python/__init__.py
@@ -34,6 +34,62 @@ class PythonBuildPack(CondaBuildPack):
self._python_version = py_version
return self._python_version
+ def get_assemble_files(self):
+ assemble_files = super().get_assemble_files()
+ for name in ('requirements.txt', 'requirements3.txt'):
+ requirements_txt = self.binder_path(name)
+ if os.path.exists(requirements_txt):
+ assemble_files.append(requirements_txt)
+ return assemble_files
+
+ def _is_local_requirement(self, line):
+ """Return whether a line in a requirements.txt file references a local file"""
+ # trim comments and skip empty lines
+ line = line.split('#', 1)[0].strip()
+ if not line:
+ return False
+ if line.startswith(('-r', '-c')):
+ # local -r or -c references break isolation
+ return True
+ # strip off `-e, etc.`
+ if line.startswith('-'):
+ line = line.split(None, 1)[1]
+ if 'file://' in line:
+ # file references break isolation
+ return True
+ if '://' in line:
+ # handle git://../local/file
+ path = line.split('://', 1)[1]
+ else:
+ path = line
+ if path.startswith('.'):
+ # references a local file
+ return True
+ return False
+
+ @property
+ def assemble_from_subset(self):
+ """Peek in requirements.txt to determine if we can assemble from only env files
+
+ If there are any local references, e.g. `-e .`,
+ stage the whole repo prior to installation.
+ """
+ if not os.path.exists('binder') and os.path.exists('setup.py'):
+ # can't install from subset if we're using setup.py
+ return False
+ for name in ('requirements.txt', 'requirements3.txt'):
+ requirements_txt = self.binder_path(name)
+ if not os.path.exists(requirements_txt):
+ continue
+ with open(requirements_txt) as f:
+ for line in f:
+ if self._is_local_requirement(line):
+ return False
+
+ # didn't find any local references,
+ # allow assembly from subset
+ return True
+
def get_assemble_scripts(self):
"""Return series of build-steps specific to this repository.
"""

check requirements.txt  for local references

allows assemble_from_subset when requirements.txt doesn't contain any local references