On Tue, Jun 12, 2018 at 01:29:32PM +0200, Laszlo Ersek wrote: > Hi Fam, > > On 06/12/18 08:41, Fam Zheng wrote: > > On Tue, 06/12 14:24, Peter Xu wrote: > >> Hi, > >> > >> For example, I wanted to compile QEMU once and install it on multiple > >> systems. What would be the suggested way to do so? > >> > >> Is there something similar to "make bin-rpmpkg" for Linux? > >> > >> Thanks in advance, > > > > No. The big question is the libraries. Even if you create the rpm, the > > libraries > > that you have linked against are not necessarily available on the systems > > you > > install. This means you either list all possible libraries as required in > > the > > rpm spec, which is a waste, or the list is generated dynamically, which is > > not > > trivial. For example, you can easily build QEMU against a custom glib, but > > it's > > very tricky to generate an rpm from it that works on other systems. > > > > For development, maybe it's easier to combine git and Ansible. > > libvirt supports RPM builds out of the upstream git tree: > > ./autogen.sh ... > make rpm > > However, while QEMU doesn't support that, Peter's idea can be solved > quite simply: > > * run QEMU's configure with "--prefix=...". For example, > --prefix=/opt/qemu-<version>. > > * If you make sure that the prefix configured above is writeable to a > non-root user, then "make install" can be executed without becoming root > first. > > * You can then tar up the installed file tree under prefix, and extract > it on other hosts (at the same absolute prefix). If the installation is > no longer needed, you can simply remove the file tree under the prefix. > > * The above procedure works basically for all open source packages > nowadays; however in order to actually use packages installed like this, > a number of environment variables may have to be extended so they refer > to various subdirectories under "prefix": > > - CPLUS_INCLUDE_PATH > (so g++ can find include files) > - C_INCLUDE_PATH > (so gcc can find include files) > - INFOPATH > (so "info" can find docs) > - LD_LIBRARY_PATH > (so ld.so can load shared objects at executable startup) > - LIBRARY_PATH > (so gcc/g++/ld can resolve "-l" options at link editing time) > - MANPATH > (so "man" can find docs) > - PATH > (so the shell finds the binary) > - PKG_CONFIG_PATH > (modern replacement for CPLUS_INCLUDE_PATH, C_INCLUDE_PATH, > and LIBRARY_PATH) > - PYTHONPATH > (so python can find python modules) > - ... > > On my laptop, I have a bunch of packages installed like this, and I have > a script that traverses /opt and generates another script that assigns > all of the above variables. This latter script is then sourced by my > ~/.bashrc. > > Considering QEMU specifically, only two of the above variables need to > be extended in practice: > > - MANPATH: append <prefix>/share/man > - PATH: append <prefix>/bin
These steps might be a bit heavy-weighted for debugging purpose of mine, but please take my sincere thanks on all these steps! I believe I could use the idea somewhere, for example, this marco list is really a good thing to know when debugging libraries with old versions. Also, the "tar + pipe" magic you offered in the other thread with Fam is nice and more light-weighted to me. I'm considering maybe I'll read about how to "make binrpm" for QEMU some day in case it'll ease some of us. > > Summary: (1) configure QEMU with option "--prefix", (2) give rwx on > "prefix" to the user that builds and installs QEMU, (3) build and > install QEMU as that user, (3) transfer the tree under prefix to another > host, (4) expand to the same prefix on the target, (5) update MANPATH > and PATH on the target. And... you even provided a summary for all the steps! Thanks again, Laszlo! -- Peter Xu