[cmake] Do not auto-turn OFF feature or auto-turn ON builtin_option

[ferdymercury]

for easy-to-install dependencies (via homebrew, apt-get)

when dependency is missing in the system. Instead, force user to install it via package manager, or to turn feature purposely OFF by hand.

Spit-off from #23015 as suggested by @guitargeek

This goes totally in-line with what's already done for asimage, zlib, etc.

[github-actions]

Test Results

    23 files      23 suites   3d 14h 35m 35s ⏱️
 3 857 tests  3 857 ✅ 0 💤 0 ❌
79 465 runs  79 465 ✅ 0 💤 0 ❌

Results for commit 375b1cb.

♻️ This comment has been updated with latest results.

[pcanal]

most ROOT builtins already call ROOT_FIND_REQUIRED_DEP which purposely bypasses this flag,

After some usage, I find this change to be indeed more pedantic (useful for system maintainer) but also annoyingly-so for the 'quickly build ROOT on this system for my private usage' (I.e. now installing ROOT on a system that does not already have the required builtin has to go through a step of parsing (by hand or mechanically) the output of cmake to find the --builtin- are that needed ... I find this onerous for a private installation).

so I am not (yet?) convinced that completely removing the feature (auto-turn on) is desirable.

[ferdymercury]

I think AI could do that parsing and -Dbuiltin=On for you to paste on the terminal. One could also improve the printed error messages so that Root already proposes -Dbuiltin1=ON ... In a one liner rather than scattered as now

now installing ROOT on a system that does not already have the required builtin has to go through a step of parsing

Can't you install instead the dependencies via homebrew or apt? So that you don't need to parse anything, just copy paste packages.txt from rootci images?

I think more developer time is spent on maintaining those many code branches (and bugs) than the time spent in writing by hand built-in On.

[pcanal]

Can't you install instead the dependencies via homebrew or apt? So that you don't need to parse anything, just copy paste packages.txt from rootci images?

I am using a system that has neither homebrew nor apt.

I think AI could do that parsing and -Dbuiltin=On for you to paste on the terminal. One could also improve the printed error messages so that Root already proposes -Dbuiltin1=ON ... In a one liner rather than scattered as now

I suspect that would help (albeit in my latest attempt they came in waves (i.e. not all were printed in the first run))

than the time spent in writing by hand built-in On.

This is hard to quantify since this is about end-user-but-I-still-build-ROOT-locally use case.

[silverweed]

now installing ROOT on a system that does not already have the required builtin has to go through a step of parsing (by hand or mechanically) the output of cmake to find the --builtin- are that needed ... I find this onerous for a private installation

I deem this to be the totally-normal process that one should expect whenever one wants to compile a package themselves...

[ferdymercury]

I suspect that would help (albeit in my latest attempt they came in waves (i.e. not all were printed in the first run))

Could you re-check now ? All messages should come all together in one wave, and the last line should be the hotfix that you could copy paste verbatim to have the required builtin_xx = ON flags.