Re: py-pydantic* dependencies

[Jonathan Perkin <jperkin%pkgsrc.org@localhost>]

* On 2025-04-22 at 11:24 BST, Havard Eidnes wrote:

> "Classic!"  No mention of what "rust stable" or "rust nightly"
> actually is in terms of versions, and no mention of when this was
> uttered.

"stable" is released versions of rust.  "nightly" is the latest version 
of rust, built every day (hence the name), that also enables features 
that have not yet made it into stable rust.

Often developers may have additional features or experimental options 
that depend on nightly unstable features, in which case they will only 
work if you have a nightly compiler.

There are lots of unstable features, some of which have remained 
unstable for a long time, because once something migrates to stable then 
it is committed to be supported forever, so obviously that only happens 
once it has been thoroughly vetted.

It is generally assumed that end-users will not have a nightly compiler 
installed, so released software will usually not depend on any nightly 
features in the default configuration.

In every rust release there is a changelog section "Stabilized APIs".  
These are all of the features that were previously only available in the 
nightly compiler that are now available for use in stable from that 
release onwards.

Rust software should ideally specify an MSRV, i.e. the earliest version 
of rust that supports all of the features that the software uses.  You 
can check for this in the "rust-version" key in Cargo.toml, for example 
my mktool utility has an MSRV of rust 1.74.0:

  https://github.com/jperkin/mktool/blob/main/Cargo.toml#L12

If you are developing rust software then there are tools that can help 
you determine what the MSRV is.

Some authors like myself will try to keep the MSRV as low as possible 
without affecting functionality.  Other authors will be more aggressive 
in their use of new stable features, given that the vast majority of 
users will be running the latest stable release.

Hope that helps,

--
Jonathan Perkin                    pkgsrc.smartos.org
Open Source Complete Cloud   www.tritondatacenter.com