Pre-release version of a package not found even with `--allow-prereleases`

[kubami]

• I am on the latest Poetry version.
• I have searched the issues of this repo and believe that this is not a duplicate.
• If an exception occurs when executing a command, I executed it again in debug mode (-vvv option).

• OS version and name: archlinux
• Poetry version: 1.1.4
• Python version: 3.7.7

Issue

I am trying to install a pre-release verion of https://github.com/elastic/enterprise-search-python

Their recommended installation method is

python -m pip install --pre elastic-enterprise-search
which works fine.

When trying to install it with poetry using

poetry add --allow-prereleases elastic-enterprise-search
I am getting an old version: 0.2.1 (the same as the one without the --allow-prereleases switch.

Am I doing something wrong? Or is it that this package is configured incorrectly?

[kubami]

when trying to install as above it doesn't work.
however when I specify the version explicitly the page installs correctly

# pyproject.toml
[tool.poetry.dependencies]
elastic-enterprise-search = {version = "7.10.0b1", allow-prereleases = true}

[markf94]

I second this! I'm unable to install pre-release versions with the --allow-prerelease flag using either Poetry 1.1.4 or 1.1.5. Even did a fresh reinstall of poetry on my system and still have the same problem. However, it does work for my colleagues with the same/similar setup.

Also verified that I can install the pre-release version when explicitly defining its version in pyproject.toml and it works in that case. However, I would like it to always pick the latest pre-release...

[ClementWalter]

I have the same problem with poetry 1.1.5. All private repos so I can't point out to the given packages, but essentially:

mypackage = { version = "^3.0.0", allow-prereleases = true}

does not resolve to using the 3.0.0.dev0 version, while if I write directly:

mypackage = { version = "^3.0.0.dev0", allow-prereleases = true}

poetry works fine.

But maybe there is a standard way of defining prerelease versions I am missing?

[alexporter8013]

looks like doing:

mypackage = { version = "^3.0.0*", allow-prereleases = true}

works fine for poetry 1.1.5 works just fine for me. If allowing pre-releases just adding a wildcard * is probably the best bet to get the latest pre-release.

[bushshrub]

I know this is an old issue but this still seems to be a problem.

[abn]

@xiurobert did you try the version on master? This might have been fixed by #5500.

[dimbleby]

I think that poetry takes the view that

• ^3.0.0 is asking for something >= 3.0.0
• 3.0.0b1 is strictly before 3.0.0

in which case I wouldn't expect #5500 to make a difference. But also it's not clear to me that this is wrong!

For instance today (poetry 1.2.0b1 exists but 1.2.0 does not):

• poetry = { version = "^1.0.0", allow-prereleases = true} does allow version 1.2.0b1 to be installed
• but poetry = { version = "^1.2.0", allow-prereleases = true} fails, finding no matching versions

which is probably correct, there is no available version that is >= 1.2.0.

Possibly this should be documented or documented better, I haven't checked what the docs do say but clearly this is confusing to lots of people.

[abn]

^3.0.0b1 == { version = "^3.0.0", allow-prereleases = true } -> this includes all pre-releases in the lowerbound. Unless the upperbound is <= pre-releases there are not included (iirc).

[dimbleby]

@abn I'm struggling to parse that! Really not sure what you mean?

[abn]

Should have explained it clearer. Effectively when searching for a compatible version ^3.0.0 with allow-prereleases = true behaves the same as ^3.0.0b1. The behaviour being, 3.0.0a1 or earlier is disallowed, 3.0.0b1 | 3.0.0b2 | 3.0.0rc1 | 3.0.0 etc. are allowed.