diff --git a/doc/languages-frameworks/python.md b/doc/languages-frameworks/python.md index 039ca8545e9..0f871395854 100644 --- a/doc/languages-frameworks/python.md +++ b/doc/languages-frameworks/python.md @@ -871,8 +871,10 @@ Executing `python setup.py bdist_wheel` in a `nix-shell `fails with ``` ValueError: ZIP does not support timestamps before 1980 ``` -This is because files are included that depend on items in the Nix store which have a timestamp of, that is, it corresponds to January the 1st, 1970 at 00:00:00. And as the error informs you, ZIP does not support that. -The command `bdist_wheel` takes into account `SOURCE_DATE_EPOCH`, and `nix-shell` sets this to 1. By setting it to a value corresponding to 1980 or later, or by unsetting it, it is possible to build wheels. + +This is because files from the Nix store (which have a timestamp of the UNIX epoch of January 1, 1970) are included in the .ZIP, but .ZIP archives follow the DOS convention of counting timestamps from 1980. + +The command `bdist_wheel` reads the `SOURCE_DATE_EPOCH` environment variable, which `nix-shell` sets to 1. Unsetting this variable or giving it a value corresponding to 1980 or later enables building wheels. Use 1980 as timestamp: ```shell @@ -882,7 +884,7 @@ or the current time: ```shell nix-shell --run "SOURCE_DATE_EPOCH=$(date +%s) python3 setup.py bdist_wheel" ``` -or unset: +or unset `SOURCE_DATE_EPOCH`: ```shell nix-shell --run "unset SOURCE_DATE_EPOCH; python3 setup.py bdist_wheel" ```