spec 文件中的 %prep 阶段，决定了源码包如何被解包、初始化与预处理。 这一节专注还原 rpm 安装日志中 %prep 对应的源码解压动作，配合日志和图片，彻底搞清楚包管理器到底做了什么。

1. %prep 阶段可视化

下面这张图可以直观看到 %prep 阶段实际对应的是源码的解压与 BUILD 目录的初始化。

实际上，这一步就是把 SOURCES 目录下的 .tar.gz 包解压出来。

2. 构建日志还原

结合实际构建日志，可以看到 rpm-build 在 %prep 阶段做了哪些解压和准备工作：

关键日志：

07:45:49.446 [QUIET] [system.out] Installing /opt/modules/bigtop/output/redis/redis_3_2_0-7.4.0-1.el8.src.rpm
07:45:49.446 [QUIET] [system.out] Executing(%prep): /bin/sh -e /var/tmp/rpm-tmp.B8k8DN
07:45:49.447 [ERROR] [system.err] + umask 022
07:45:49.447 [ERROR] [system.err] + cd /opt/modules/bigtop/build/redis/rpm//BUILD
07:45:49.447 [ERROR] [system.err] + cd /opt/modules/bigtop/build/redis/rpm/BUILD
07:45:49.447 [ERROR] [system.err] + rm -rf redis-7.4.0
07:45:49.449 [ERROR] [system.err] + /usr/bin/gzip -dc /opt/modules/bigtop/build/redis/rpm/SOURCES/7.4.0.tar.gz
07:45:49.450 [ERROR] [system.err] + /usr/bin/tar -xvvof -

这里已经非常明确：

• 先清空旧的 BUILD 目录
• 再把 SOURCES 目录下的源码 tar 包解压
• 解包后，redis-7.4.0 目录内容完全展开

3. 解包结构与文件还原

实际执行过程中，解压出来的内容如下（部分日志截取）：

/usr/bin:/sbin:/bin:/opt/modules/gradle-5.6.4/bin:/opt/modules/apache-ant-1.10.12/bin:/opt/modules/apache-ivy-2.5.0/bin:/opt/modules/jdk1.8.0_202/bin, HISTCONTROL=ignoredups
, CONDA_DEFAULT_ENV=base, CONDA_EXE=/opt/enhance_env/miniconda3/bin/conda, HISTSIZE=1000, JAVA_HOME=/opt/modules/jdk1.8.0_202, IMPALA_HOME=/opt/modules/bigtop/build/impala/r
pm/BUILD/impala-4.4.1, BASH_FUNC_which%%=() {  ( alias;
 eval ${which_declare} ) | /usr/bin/which --tty-only --read-alias --read-functions --show-tilde --show-dot $@
}, CONDA_PYTHON_EXE=/opt/enhance_env/miniconda3/bin/python, TERM=xterm, LANG=C.UTF-8, GRADLE_HOME=/opt/modules/gradle-5.6.4, CONDA_PREFIX=/opt/enhance_env/miniconda3, ANT_HO
ME=/opt/modules/apache-ant-1.10.12, MAVEN_HOME=/opt/modules/apache-maven-3.8.4, MAIL=/var/spool/mail/root, NVM_INC=/root/.nvm/versions/node/v12.13.0/include/node, _CE_M=, wh
ich_declare=declare -f, LOGNAME=root, NVM_NODEJS_ORG_MIRROR=https://npmmirror.com/mirrors/node, PWD=/opt/modules/bigtop, CONDA_SHLVL=1, NVM_CD_FLAGS=, NVM_DIR=/root/.nvm, LE
SSOPEN=||/usr/bin/lesspipe.sh %s, R_HOME=/usr/local/R-4.4.2, OLDPWD=/opt/modules/gradle-5.6.4, USER=root, _CE_CONDA=, HOSTNAME=rocky8, DEBUGINFOD_URLS=https://debuginfod.cen
tos.org/ , CONDA_PROMPT_MODIFIER=(base) , IVY_HOME=/opt/modules/apache-ivy-2.5.0, QA_RPATHS=2, NVM_BIN=/root/.nvm/versions/node/v12.13.0/bin, HOME=/root, SHLVL=1}
07:45:49.418 [DEBUG] [org.gradle.process.internal.DefaultExecHandle] Changing state to: STARTING
07:45:49.418 [DEBUG] [org.gradle.process.internal.DefaultExecHandle] Waiting until process started: command 'rpmbuild'.
07:45:49.422 [DEBUG] [org.gradle.process.internal.DefaultExecHandle] Changing state to: STARTED
07:45:49.422 [INFO] [org.gradle.process.internal.DefaultExecHandle] Successfully started process 'command 'rpmbuild''
07:45:49.422 [DEBUG] [org.gradle.process.internal.ExecHandleRunner] waiting until streams are handled...
07:45:49.446 [QUIET] [system.out] Installing /opt/modules/bigtop/output/redis/redis_3_2_0-7.4.0-1.el8.src.rpm
07:45:49.446 [QUIET] [system.out] Executing(%prep): /bin/sh -e /var/tmp/rpm-tmp.B8k8DN
07:45:49.447 [ERROR] [system.err] + umask 022
07:45:49.447 [ERROR] [system.err] + cd /opt/modules/bigtop/build/redis/rpm//BUILD
07:45:49.447 [ERROR] [system.err] + cd /opt/modules/bigtop/build/redis/rpm/BUILD
07:45:49.447 [ERROR] [system.err] + rm -rf redis-7.4.0
07:45:49.449 [ERROR] [system.err] + /usr/bin/gzip -dc /opt/modules/bigtop/build/redis/rpm/SOURCES/7.4.0.tar.gz
07:45:49.450 [ERROR] [system.err] + /usr/bin/tar -xvvof -
07:45:49.451 [QUIET] [system.out] drwxrwxr-x root/root         0 2024-07-29 05:31 redis-7.4.0/
07:45:49.451 [QUIET] [system.out] drwxrwxr-x root/root         0 2024-07-29 05:31 redis-7.4.0/.codespell/
07:45:49.451 [QUIET] [system.out] -rw-rw-r-- root/root       139 2024-07-29 05:31 redis-7.4.0/.codespell/.codespellrc
07:45:49.451 [QUIET] [system.out] -rw-rw-r-- root/root        17 2024-07-29 05:31 redis-7.4.0/.codespell/requirements.txt
07:45:49.451 [QUIET] [system.out] -rw-rw-r-- root/root       111 2024-07-29 05:31 redis-7.4.0/.codespell/wordlist.txt
07:45:49.452 [QUIET] [system.out] -rw-rw-r-- root/root       405 2024-07-29 05:31 redis-7.4.0/.gitattributes
07:45:49.452 [QUIET] [system.out] drwxrwxr-x root/root         0 2024-07-29 05:31 redis-7.4.0/.github/
07:45:49.452 [QUIET] [system.out] drwxrwxr-x root/root         0 2024-07-29 05:31 redis-7.4.0/.github/ISSUE_TEMPLATE/
07:45:49.452 [QUIET] [system.out] -rw-rw-r-- root/root       409 2024-07-29 05:31 redis-7.4.0/.github/ISSUE_TEMPLATE/bug_report.md
07:45:49.452 [QUIET] [system.out] -rw-rw-r-- root/root       580 2024-07-29 05:31 redis-7.4.0/.github/ISSUE_TEMPLATE/crash_report.md
07:45:49.452 [QUIET] [system.out] -rw-rw-r-- root/root       623 2024-07-29 05:31 redis-7.4.0/.github/ISSUE_TEMPLATE/feature_request.md
07:45:49.452 [QUIET] [system.out] -rw-rw-r-- root/root       110 2024-07-29 05:31 redis-7.4.0/.github/ISSUE_TEMPLATE/other_stuff.md
07:45:49.452 [QUIET] [system.out] -rw-rw-r-- root/root       941 2024-07-29 05:31 redis-7.4.0/.github/ISSUE_TEMPLATE/question.md
07:45:49.452 [QUIET] [system.out] -rw-rw-r-- root/root       526 2024-07-29 05:31 redis-7.4.0/.github/dependabot.yml
07:45:49.452 [QUIET] [system.out] drwxrwxr-x root/root         0 2024-07-29 05:31 redis-7.4.0/.github/workflows/
07:45:49.453 [QUIET] [system.out] -rw-rw-r-- root/root      3029 2024-07-29 05:31 redis-7.4.0/.github/workflows/ci.yml
07:45:49.453 [QUIET] [system.out] -rw-rw-r-- root/root       706 2024-07-29 05:31 redis-7.4.0/.github/workflows/codeql-analysis.yml
07:45:49.453 [QUIET] [system.out] -rw-rw-r-- root/root      1322 2024-07-29 05:31 redis-7.4.0/.github/workflows/coverity.yml
07:45:49.453 [QUIET] [system.out] -rw-rw-r-- root/root     56666 2024-07-29 05:31 redis-7.4.0/.github/workflows/daily.yml
07:45:49.453 [QUIET] [system.out] -rw-rw-r-- root/root      2737 2024-07-29 05:31 redis-7.4.0/.github/workflows/external.yml
07:45:

这些都是源码包的完整目录，%prep 只是把压缩包内容标准化还原到 BUILD 目录下。

4. 解压后的目录

如上图，%prep 阶段完成后，源码被完整解压到 rpm 的 BUILD 目录下，目录结构与源码包一致：

• 顶层目录为：redis-7.4.0/
• 其中包含 README.md、Makefile、deps/、src/、tests/ 等全部源码文件和子目录

实际路径如下：

/opt/modules/bigtop/build/redis/rpm/BUILD/redis-7.4.0/

后续所有的构建、补丁、安装等操作都在这个目录内展开。