I work on closed networks that have no internet connection. Approved Python packages are typically given to me as sdists downloaded from Pypi. One such package is PEP517 compliant. When I attempt to install that package, pip attempts to build the package in isolation by downloading the requirements, which is not possible, so pip fails. What’s surprising to me is that being unable to achieve an isolated build environment is considered a failure and the package is not installed.
The build requirements for this package are already satisfied, and I can currently circumvent the issue using
--no-use-pep517. Are they really the recommended solution? Is there some argument against pip using existing installations of required packages if it fails to obtain them for an isolated build?
I’m proposing that pip continue to install PEP517 compliant packages, even if build isolation was not possible.
- Build isolation is not required according to the language in the PEP.
- Being able to obtain newer packages for build isolation shouldn’t be an issue for 99.9% of people, so I don’t think this violates the spirit of the PEP.