无论Rd文件是否包含\PR{}，R CMD build的行为都不同。有关宏的详细信息，请参阅编写R扩展。
Rd文件不包含\PR{}时的示例：

$ R CMD build test
* checking for file 'test/DESCRIPTION' ... OK
* preparing 'test':
* checking DESCRIPTION meta-information ... OK
* installing the package to process help pages
* saving partial Rd database
* checking for LF line-endings in source and make files and shell scripts
* checking for empty or unneeded directories
* building 'test_0.1.tar.gz'

Rd文件包含\PR{}时的示例：

$ R CMD build test
* checking for file 'test/DESCRIPTION' ... OK
* preparing 'test':
* checking DESCRIPTION meta-information ... OK
* installing the package to process help pages
* saving partial Rd database
* building the PDF package manual      # <- this
Hmm ... looks like a package           # <- this
Converting Rd files to LaTeX           # <- this
Creating pdf output from LaTeX ...     # <- this
Saving output to 'xxx/test.pdf' ...    # <- this
Done                                   # <- this
* checking for LF line-endings in source and make files and shell scripts
* checking for empty or unneeded directories
* building 'test_0.1.tar.gz'

额外的阶段（即building the PDF package manual，在旧计算机上可能相当慢...）是由于.build_packages()中对..Rd2pdf()的调用。但是我不明白是什么触发了这个阶段。此外，它只对\PR{}触发，而不对其他宏（如\CRANpkg{}和\doi{}）触发。
有人能追溯发生了什么以及为什么吗？问题只针对base R函数。我不使用package:devtools这样的助手。

最小测试包

Package 结构：

test
test/man
test/man/one.Rd
test/R
test/R/one.R
test/DESCRIPTION
test/NAMESPACE

test/man/one.Rd：

\name{one}
\alias{one}
\title{Get One}
\description{
Rd file containing or not the PR macro:
\PR{1} % comment/uncomment this line as needed
but containing other macros:
\CRANpkg{ggplot2} and \doi{10.1002/wics.147}
}
\usage{
one()
}

test/R/one.R：

one <- function() 1

test/DESCRIPTION：

Package: test
Version: 0.1
Title: Test
Author: Nobody
Maintainer: Nobody <no@body.org>
Description: Test.
License: GPL-3

test/NAMESPACE：

export(one)

使用以下工具生成、检查和安装：

$ R CMD build test
$ R CMD check test_0.1.tar.gz
$ R CMD INSTALL test_0.1.tar.gz