ENH: Adding eon

[HaoZeke]

This is for https://theochemui.github.io/eOn/

A test for this build was first on a private forge.

Checklist

• Title of this PR is meaningful: e.g. "Adding my_nifty_package", not "updated meta.yaml".
• License file is packaged (see here for an example).
• Source is from official source.
• Package does not vendor other packages. (If a package uses the source of another package, they should be separate packages or the licenses of all packages need to be packaged).
• [ ] If static libraries are linked in, the license of the static library is packaged.
• Package does not ship static libraries. If static libraries are needed, follow CFEP-18.
• Build number is 0.
• A tarball (url) rather than a repo (e.g. git_url) is used in your recipe (see here for more details).
• GitHub users listed in the maintainer section have posted a comment confirming they are willing to be listed there.
• When in trouble, please check our knowledge base documentation before pinging a team.

[HaoZeke]

As the contributor and current maintainer I agree to be listed.

[HaoZeke]

@conda-forge/help-c-cpp

[github-actions]

Hi! This is the staged-recipes linter and your PR looks excellent! 🚀

[conda-forge-admin]

Hi! This is the friendly automated conda-forge-linting service.

I wanted to let you know that I linted all conda-recipes in your PR (recipes/eon/recipe.yaml) and found some lint.

Here's what I've got...

For recipes/eon/recipe.yaml:

• ❌ When defining a source/url please add a sha256, sha1 or md5 checksum (sha256 preferably).

For recipes/eon/recipe.yaml:

• ℹ️ Jinja2 variable references are suggested to take a ${{<one space><variable name><one space>}} form. See lines [35].

_{This message was generated by GitHub Actions workflow run https://github.com/conda-forge/conda-forge-webservices/actions/runs/16694198187. Examine the logs at this URL for more detail.}

[conda-forge-admin]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipes/eon/recipe.yaml) and found it was in an excellent condition.

I do have some suggestions for making it better though...

For recipes/eon/recipe.yaml:

• ℹ️ Jinja2 variable references are suggested to take a ${{<one space><variable name><one space>}} form. See lines [36].

_{This message was generated by GitHub Actions workflow run https://github.com/conda-forge/conda-forge-webservices/actions/runs/16694227784. Examine the logs at this URL for more detail.}

[conda-forge-admin]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipes/eon/recipe.yaml) and found it was in an excellent condition.

[HaoZeke]

Kinda stumped by the error, since the variant should cover this:

In file included from ../client/Parameters.cpp:11:
 │ │ ../client/NudgedElasticBand.h:98:49: error: 'path' is unavailable: introduced in macOS 10.15 unknown - see https://conda-forge.org/docs/maintainer/knowledge_base.html#newer-c-features-with-old-sdk
 │ │    98 | filePathInit(const std::vector<std::filesystem::path> &fsrcs,
 │ │       |                                                 ^
 │ │ $PREFIX/bin/../include/c++/v1/__filesystem/path.h:381:33: note: 'path' has been explicitly marked unavailable here
 │ │   381 | class _LIBCPP_EXPORTED_FROM_ABI path {
 │ │       |                                 ^

Needed -D_LIBCPP_DISABLE_AVAILABILITY

[HaoZeke]

@conda-forge/help-c-cpp, ready for review!