Proposal: use metapackage for jderobot-deps & jderobot-devs

[varhub]

Proposal: use metapackage for jderobot-deps & jderobot-devs

Using described steps at http://jeffhoogland.blogspot.com.es/2011/08/howto-create-debian-meta-package.html, we can generate a metapackage with no code, so it targets to all architectures.
Therefore, make steps are no longer required.

What it implies?

jderobot - Jderobot .deb as always (the only one with code)
jderobot-deps - binary dependencies of Jderobot
jderobot-deps-dev - headers of libraries

Looping the loop

jderobot-dev-tools - for cmake, git, build-essential, pkg-config
jderobot-all - includes all above

How it works

1. Just create a "fake" hierarchy
   mkdir -p pkg_name/DEBIAN/
2. Fill it with .deb info (apt-cache show | dpkg --info)
   edit pkg_name/DEBIAN/control
3. Build (create) package
   dpkg --build pkg_name

Pros and cons

• It is decoupled to jderobot code
  • (pro) jderobot forget requirements for cpack
  • (cons) metapackage can become deprecated (out-of-sync)
• No more embedded into cpack
• Requires explicit command line execution

Remember

Use Architecture: all, so it works for any target ;)

Since these metapackages are fake ones, and gather all required dependencies, push it here could be a good idea. (It's only text, so have it in git will increase commodity and clarity).

[varhub]

Update (dpkg-shlibdeps)

I noticed a little fail in my proposal, CPack does it better, so jderobot-deps begans to be we stupid.

Reason

At now, dpkg-shlibdeps list all required dependencies and format it in a apt-get way (pretty well). But also enforces minimal compatible version.

Doing it externally will let required version incomplete (letting it to apt-get criteria).

Implications

• CPack must maintain his format, so jderobot must not depend on jderobot-deps unless for cpack restrictions (impossibility to trim dependencies for core only).
• jderobot-deps is only a copy paste of CPack generated dependencies
• jderobot-deps-dev currently has not information about minimal required version. Convolve jderobot-deps with jderobot-deps-devs (install both in same call) will solve partially this issue.
• jderobot-deps-devs should be generated with a script that search -dev based version of dependency listed at jderobot-deps. Therefore, we can transfer version constrain.

Further implications (guess it)

• What criteria follows CPack to complete version info?
  • If it uses installed version as lower bound, jderobot-deps will make sense, because we can explicitly downgrade version if we want.
• Is there some way/method to locate package of headers for a package library?
  • What means Source: at dpkg? Can it be used? (update: cannot)

[varhub]

Example

If you are in Linux, please, download my branch and run make_packages.sh

git clone https://github.com/varhub/JdeRobot-ThirdParty.git -b package-generator
cd JdeRobot-ThirdParty/metapackages
./make_packages.sh
cd build
dpkg --info jderobot-deps.deb

Finally, test it with:

1. dpkg -i jderobot-deps.deb jderobot-deps-dev.deb
2. apt-get install --simulate -f
3. dpkg -r jderobot-deps jderobot-deps-dev

Dry run test! do not be worried

http://superuser.com/questions/196864/how-to-install-local-deb-packages-with-apt-get