Mention full JDK as a prerequisite

[khinsen]

CIDER apparently needs a full JDK (see #3339), rather than just a Java runtime. This is not obvious, so it should be stated explicitly in the list of prerequisites.

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[vemv]

Thanks for finding this missing spot!

[vemv]

Suggested change

	Make sure you have a complete JDK installation. Many Linux distributions
	provide only the runtime support by default.
	On Linux you are also strongly advised to make sure that JDK sources and javadocs are installed.
	You can find example commands in xref:troubleshooting.adoc#navigation-to-jdk-sources-doesnt-work[Troubleshooting].

I took that from https://docs.cider.mx/cider/about/compatibility.html#java . Probably it's a good idea so simply have the same paragraph/link twice.

[bbatsov]

Generally the full JDK is needed only if people are using cider-nrepl, but I guess that's most of the users anyways.

[bbatsov]

So, what will we have here as the final wording?

[khinsen]

I'd prefer something that is clear to newcomers, who are the most in need of installation instructions. That's people who know very little about CIDER and probably even nREPL. When I read "strongly advised to make sure that JDK sources and javadocs are installed", I am left wondering why JDK sources and javadocs matter for CIDER, given that they are "strongly advised" but not required.

If you want to send the message that experienced users should investigate this for themselves, then I'd write "Unless you know what you are doing, install a full JDK with sources and javadocs".

[vemv]

Thanks for the input!

I changed strongly advised to required. Which sounds slightly stringent, but it will leave things clear beyond any doubt.

Unless you know what you are doing, install a full JDK with sources and javadocs

I considered this one but it kind of invites adventurous devs to try random things? 😄