[qt5-base]Add a print message to inform the user to install the dependency package.

[JackBoosY]

When qt5 is installed in Linux, we need two packages:

• libgl1-mesa-dev
• libglu1-mesa-dev

And users may not have installed them, so I added a print message to inform to install them.

[TheScarfix]

not every disto uses apt though. is there a way to not exclude RPM and other package managers?

[cenit]

Usually we just write a message to the user.
I also don't like this approach, because it's messing the system outside the vcpkg folder ;)

[Rastaban]

Switch to just printing out a message. If mesa is required on linux then you could check if it is installed and then print an error message that has the apt command.

[MVoz]

cmake is it will run in interactive mode?
sudo means entering a password

Yes, and many it just does not install, due to the many dependencies

I think it is necessary to do Mesa port it is more reasonable option

[TheScarfix]

I would like a change from apt-get to "the package manager of your distribution" or something like that :)

[JackBoosY]

/azp run

[JackBoosY]

@Rastaban PR-Eager error is due to download source failed, I just added two lines of message.

[MVoz]

@JackBoosY message(STATUS ? or warning

[JackBoosY]

@voskrese Using status to notify users is not a good idea because it may be confused with other status information.
And I am considering whether I can add a new option to highlight these tips.

[MVoz]

color ?

example

if(VCPKG_CMAKE_SYSTEM_NAME STREQUAL Linux OR Darwin)
if(NOT WIN32)
     string(ASCII 27 ESCAPE)
     set(BoldRed "${ESCAPE}[31;2m")
     set(ColourReset "${ESCAPE}[0m")
endif()
     message(FATAL_ERROR "${BoldRed} --== ONLY WINDOWS OS ==-- ${ColourReset}")
endif(VCPKG_CMAKE_SYSTEM_NAME STREQUAL Linux OR Darwin)

[JackBoosY]

@voskrese Such as: message(USER_WARNING "something needs to notify user")

[heydojo]

Why not proc for the existence of the header file(s) the build requires?

The variable INCLUDEPATH usually holds the includes on Linux systems AFAIK and something more like :

    if(EXISTS ${INCLUDEPATH}/mesa/someheader.h)
        message(STATUS "Found required external dependency someheader.h")
    else()
        message(FATAL_ERROR "Please install the required packages containing someheader.h using your distribution's software manager. On Debian Linux the packages are named: libgl1-mesa-dev and libglu1-mesa-dev")
    endif()

I will add too that Fedora, OpenSuse, Manjaro, Mint, Arch and Alpine likely won't all share the same names for these packages. Which creates another problem.

[JackBoosY]

@heydojo Sorry, I‘m not sure which header file should be used to check the packages. Can you provide them?

[heydojo]

@heydojo Sorry, I‘m not sure which header file should be used to check the packages. Can you provide them?

Dependency resolution for things like this is one of cmake's strong points.
As vcpkg is (in it's most basic of definitions) a layer on top of cmake, I would assume that you are familiar enough with cmake to check for the required headers?

When looking for mesa GLU:
https://apps.fedoraproject.org/packages/s/mesa
https://apps.fedoraproject.org/packages/mesa-libGLU-devel
https://koji.fedoraproject.org/koji/rpminfo?rpmID=16484448
https://koji.fedoraproject.org/koji/rpminfo?rpmID=16484445

Looks like you are looking for the file /usr/include/GL/glu.h
found inside the package mesa-libGLU-devel in Fedora (and likely RHEL & CentOS too.)

Other Linux variants you would need to check yourself. I don't use or recommend any others.
Hopefully this info is useful.

[Rastaban]

This is consistent with how other packages handle external dependencies on Linux so I am okay with the current state of this PR. Adding the check for glu.h and turning the message into a fatal error if not found would be a good improvement though.