curl/docs/DEPRECATE.md

Items to be removed from future curl releases

If any of these deprecated features is a cause for concern for you, please email the curl-library mailing list as soon as possible and explain to us why this is a problem for you and how your use case cannot be satisfied properly using a workaround.

NSS

We remove support for building curl with the NSS TLS library in August 2023.

• There are few users left who use curl+NSS
• NSS has few users outside of curl as well (primarily Firefox)
• NSS is harder than ever to find documentation for
• NSS was always "best" used with Red Hat Linux when they provided additional features on top of the regular NSS that is not shipped by the vanilla library

Starting in 7.82.0, building curl to use NSS configure requires the additional flag --with-nss-deprecated in an attempt to highlight these plans.

gskit

We remove support for building curl with the gskit TLS library in August 2023.

• This is a niche TLS library, only running on some IBM systems
• no regular curl contributors use this backend
• no CI builds use or verify this backend
• gskit, or the curl adaption for it, lacks many modern TLS features making it an inferior solution
• build breakages in this code take weeks or more to get detected
• fixing gskit code is mostly done "flying blind"

mingw v1

We remove support for building curl with the original legacy mingw version 1 in September 2023.

During the deprecation period you can enable the support with the configure option --with-mingw1-deprecated.

mingw version 1 is old and deprecated software. There are much better and still support build environments to use to build curl and other software. For example MinGW-w64.

space-separated NOPROXY patterns

When specifying patterns/domain names for curl that should not go through a proxy, the curl tool features the --noproxy command line option and the library supports the NO_PROXY environment variable and the CURLOPT_NOPROXY libcurl option.

They all set the same list of patterns. This list is documented to be a set of comma-separated names, but can also be provided separated with just space. The ability to just use spaces for this has never been documented but some users may still have come to rely on this.

Several other tools and utilities also parse the NO_PROXY environment variable but do not consider a space to be a valid separator. Using spaces for separator is probably less portable and might cause more friction than commas do. Users should use commas for this for greater portability.

curl will remove the support for space-separated names in July 2024.

past removals

• Pipelining
• axTLS
• PolarSSL
• NPN
• Support for systems without 64 bit data types