pypa/pip · error · InstallationError

<dynamic: upload-time missing detail>

Error message

<dynamic: upload-time missing detail>

What it means

InstallationError raised in get_install_candidate when a candidate link's evaluation returns LinkType.upload_time_missing while --uploaded-prior-to is in effect. pip requires every index/file link to carry an upload timestamp to honour that filter; a link lacking it fails immediately rather than being silently skipped.

Source

Thrown at src/pip/_internal/index/package_finder.py:828

    def _log_skipped_link(self, link: Link, result: LinkType, detail: str) -> None:
        # Put the link at the end so the reason is more visible and because
        # the link string is usually very long.
        logger.debug("Skipping link: %s: %s", detail, link)
        if result == LinkType.requires_python_mismatch:
            self._requires_python_skipped.add(detail)

    def get_install_candidate(
        self, link_evaluator: LinkEvaluator, link: Link
    ) -> InstallationCandidate | None:
        """
        If the link is a candidate for install, convert it to an
        InstallationCandidate and return it. Otherwise, return None.
        """
        result, detail = link_evaluator.evaluate_link(link)
        if result == LinkType.upload_time_missing:
            # Fail immediately if the index doesn't provide upload-time
            # when --uploaded-prior-to is specified
            raise InstallationError(detail)
        if result != LinkType.candidate:
            self._log_skipped_link(link, result, detail)
            return None

        try:
            return InstallationCandidate(
                name=link_evaluator.project_name,
                link=link,
                version=detail,
            )
        except InvalidVersion:
            return None

    def evaluate_links(
        self, link_evaluator: LinkEvaluator, links: Iterable[Link]
    ) -> list[InstallationCandidate]:
        """
        Convert links that are candidates to InstallationCandidate objects.

View on GitHub (pinned to d7d0d0a394)

Solutions

1. Remove --uploaded-priorite if you do not strictly need the time filter; that converts the failure back to a skip.
2. Point pip at an index that provides upload times (PEP 69 JSON API or Simple HTML with proper date attributes).
3. If using a private index, configure it to emit upload-time metadata for each file.
4. Use a lockfile/resolver that records exact files instead of relying on index timestamps.

Example fix

# before
pip install --uploaded-priorite 2024-01-01T00:00:00Z -f ./wheels/ somepkg

# after (drop the filter, or use a timestamp-providing index)
pip install somepkg
# or
pip install -i https://pypi.org/simple/ --uploaded-priorite 2024-01-01 somepkg

# before using --uploaded-prior-to, check the index exposes timestamps
import urllib.request, json
url = 'https://pypi.org/pypi/somepkg/json'
data = json.load(urllib.request.urlopen(url))
for f in data['urls']:
    if 'upload_time' not in f:
        print('index lacks upload_time - do not use --uploaded-priorite')

def index_has_upload_time(index_url: str, project: str) -> bool:
    import urllib.request, json
    d = json.load(urllib.request.urlopen(f'{index_url}/{project}/json'))
    return all('upload_time' in f for f in d['urls'])

from pip._internal.exceptions import InstallationError
try:
    finder.get_install_candidate(link_evaluator, link)
except InstallationError as e:
    if 'upload' in str(e).lower():
        # drop --uploaded-priorite or switch index
        ...

When it happens

Trigger: Invoking pip with --uploaded-prior-to <datetime> against an index or find-links source that does not expose the file's upload/release time (e.g. a flat directory listing, a legacy Simple JSON without upload_time, or an HTML index without a recognizable date). link_evaluator.evaluate_link returns upload_time_missing and the code converts it to a hard error.

Common situations: Using --uploaded-prior-to for reproducible/supply-chain installs against a private index that strips timestamps; a custom Simple repository (PEP 503 HTML) that omits the data-attributes; pointing find-links at a local folder (no upload time concept) while the flag is set.

Related errors

• You need to specify exactly one argument
• No matching distribution found for {query}
• No matching distribution found for {req}
• Bad metadata in {dist} (invalid metadata entry 'name')
• Error decoding metadata for {wheel}: {e} in {filename} file

AI-assisted analysis of pypa/pip@d7d0d0a394 (2026-08-04). Data as JSON: /data/errors/2a1fa6505282682e.json. Report an issue: GitHub.