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

• 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?

[bomber8013]

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.

[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?