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{{Chris Tyler Draft}}[[Category:SPO600 Labs]]{{Admon/lab|Purpose of this Lab|In this lab, you will do a baseline build of a software package.}}

# ==== Build an open source software package====## Select an open source software package from the [http://www.gnu.org/software/software.html Free Software Foundation's GNU Project] or another open source project.## Download the source code for the software. (Do not install with dnf/yum!)## Build the software. You may need to install build dependencies (e.g., compilers, tools, and libraries); you can do this (and only this) as the root user.## Without installing the new software that you just build (because that could override the existing and working version), test that it works.# Blog your results. Explain (don't just document) each of the steps required to build your software and any dependencies you need to install. Include your reflections on the process. ==== Build and test glibc ===={{Admon/importanttip|Read the glibc Instructions|The glibc software and build system are complex, since this is core library which underlies most of the software on the system. [https://www.gnu.org/software/libc/ Read the documentation carefully.]}}# Build and test glibc## Find and build the source code for the latest released version of the GNU Standard C Library (glibc). Note that glibc uses two parallel directory trees: one which contains the source code, and one which contains configuration and the output of the build system. You can safely delete all of the contents of the build directory and rebuild at any time.## Test the library which you have built (Critical: do this without installing it on your system and overwriting your existing glibc installation!). Prove that your version of the library is used in your tests by introducing a change in behaviour (for example, a small bug).## There may be multiple implementations of a function: a basic version, written in C, and one or more versions for the target architecture. Learn the mechanisms used to override one implementation with another. Read up on the multiarch system.## Blog about the process, your results, your observations, and what you learned.## Obtain the source code for glibc via git using the instructions at https://sourceware.org/glibc/wiki/Testing/Builds## Build and test your version of glibc. '''Do Not''' install it into the system directories or you may destroy the existing Linux installation!# Blog about your results. Provide convincing proof that you can test the specific version of glibc which you build. Explain override and multiarch mechanisms.