x/website: make supported OS versions easier to find

[rsc]

I spent a long time just now trying to identify which versions of Go support which operating system versions.
I thought this used to be documented on the install page.
All I can find is the text inside the "featured download" buttons on https://golang.org/dl/.
That can't be the only source for this info.
FreeBSD is a first-class port but not a featured download.
What version of FreeBSD do we support?
I can't find out.

https://golang.org/doc/install/source links back to /doc/install for "overall system requirements".

It is possible that the recent install page rewrite is what dropped the info, and we need to bring it back one way or another.

[stevetraut]

The original file at https://golang.org/doc/install had the information below under "System Requirements". It did not map every Go version to every OS version on which that Go was supported.

I can create a new file at https://golang.org/doc/system-requirements and add it to the website repo. We'll need to cobble together the Go version-to-OS-version mapping to add there -- I don't see that doc'ed anywhere. https://golang.org/dl/ appears to be as close as we get, and that doesn't list OS versions (just OSes).

I'll keep hunting for a full mapping. Or if we had it, it might have been removed.

---

Operating system	Architectures	Notes
FreeBSD 10.3 or later	amd64, 386	Debian GNU/kFreeBSD not supported
Linux 2.6.23 or later with glibc	amd64, 386, arm, arm64,s390x, ppc64le	CentOS/RHEL 5.x not supported.Install from source for other libc.
macOS 10.11 or later	amd64	use the clang or gcc† that comes with Xcode‡ for cgo support
Windows 7, Server 2008R2 or later	amd64, 386	use MinGW (386) or MinGW-W64 (amd64) gcc†.No need for cygwin or msys.

[dmitshur]

This is a valid issue that we've been aware of for some time. I thought we already had an open issue tracking this, but after looking, I can't find it. So let's use this one.

The best currently available sources of information I'm aware of, which require a lot of mental mapping and reading that we wanted to consolidate on one clear page, include:

• https://golang.org/dl/ which list the requirements of the latest major release (under featured downloads)
  • this is insufficient for knowing what the requirements of the previous major release are, requiring digging in x/website commit history to find out
• a table on the previous version of the https://golang.org/doc/install#requirements page (see here)
• release notes for major Go releases
  • e.g., https://golang.org/doc/go1.13#freebsd has the information that Go 1.13 started to require FreeBSD 11.2 or later
• https://golang.org/wiki/PortingPolicy#first-class-ports for the official list of first-class ports
  • note that we distribute binaries for some ports which are not first-class

There's also a wiki page https://golang.org/wiki/MinimumRequirements, but I don't know how well maintained that is.

/cc @andybons @cagedmantis @toothrot

[gopherbot]

Change https://go.dev/cl/424575 mentions this issue: _content/doc/install: add link to the minimum requirements wiki page