R CMD检查 - 包可以安装但无法加载

Question

我创建了一个名为letstrythis 的测试包来说明问题。测试包非常简单，包含以下文件：

• DESCRIPTION

  Package: letstrythis
  Title: What the Package Does (one line, title case)
  Version: 0.0.0.9000
  Authors@R: person("Mike", "Smith", email = "Mike.Smith@anything.com", role = c("aut", "cre"))
  Description: letstrythis is great.
  Depends:
      R (>= 3.2.3)
  License: GPL
  LazyData: true
  Maintainer: 'Mike Smith' <Mike.Smith@anything.com>
  RoxygenNote: 5.0.1
  

• NAMESPACE

  # Generated by roxygen2: do not edit by hand
  export(add_numbers)
  

• R/add-numbers.R

  #' test function
  #'
  #' @param x numeric
  #' @param y numeric
  #' @return numeric
  #' @export
  #'
  #' @examples
  #' add_numbers(1, 1)
  #' add_numbers(2, 3)
  
  
  add_numbers <- function(x, y) {
    x + y
  }
  

和

• man/add_numbers.Rd

由 roxygen2 自动创建。

每次我使用devtools::check() 检查我的包裹时，都会收到以下错误消息：

* checking examples ... ERROR
Running examples in 'letstrythis-Ex.R' failed
The error occurred in:

R version 3.2.3 (2015-12-10) -- "Wooden Christmas-Tree"
Copyright (C) 2015 The R Foundation for Statistical Computing
Platform: x86_64-w64-mingw32/x64 (64-bit)

R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under certain conditions.
Type 'license()' or 'licence()' for distribution details.

  Natural language support but running in an English locale

R is a collaborative project with many contributors.
Type 'contributors()' for more information and
'citation()' on how to cite R or R packages in publications.

Type 'demo()' for some demos, 'help()' for on-line help, or
'help.start()' for an HTML browser interface to help.
Type 'q()' to quit R.

> pkgname <- "letstrythis"
> source(file.path(R.home("share"), "R", "examples-header.R"))
> options(warn = 1)
> options(pager = "console")
> base::assign(".ExTimings", "letstrythis-Ex.timings", pos = 'CheckExEnv')
> base::cat("name\tuser\tsystem\telapsed\n", file=base::get(".ExTimings", pos = 'CheckExEnv'))
> base::assign(".format_ptime",
+ function(x) {
+   if(!is.na(x[4L])) x[1L] <- x[1L] + x[4L]
+   if(!is.na(x[5L])) x[2L] <- x[2L] + x[5L]
+   options(OutDec = '.')
+   format(x[1L:3L], digits = 7L)
+ },
+ pos = 'CheckExEnv')
> 
> ### * </HEADER>
> library('letstrythis')
Error in library("letstrythis") : 
  there is no package called 'letstrythis'
Execution halted
* checking PDF version of manual ... OK
* DONE
Status: 1 ERROR

See
  'Z:/R_codes/letstrythis.Rcheck/00check.log'
for details.

Error: Command failed (1)
Execution halted

Exited with status 1.

显然，每次执行R/add-numbers.R 中的示例时，都无法使用library() 加载包。

Answer 1

在调用library() 时设置库位置会有所帮助。在编写将要发布的一般示例时，这可能不是理想的解决方案。对我来说，在 devtools::check() 期间运行测试时很有帮助。在网络驱动器上工作时我遇到了同样的问题，即无法通过library() 加载tests/testthat.R 中指定的包。我没有将正在开发的整个包复制到本地驱动器，而是使用了命令

library(package_under_dev, lib.loc = "..")

在tests/testthat.R 文件中。该命令将从当前工作目录的根目录加载包。这在devtools::check() 期间很有用，因为它将使 R 使用位于临时 package_under_dev.Rcheck 文件夹中的干净包，该文件夹是在检查例程期间创建的。

或者，也可以通过

将根文件夹添加到搜索路径

.libPaths(c("..", .libPaths()))

然后不需要在对library() 的调用中指定它。在check()ing 示例的情况下，这可能会有所帮助。

按照here 的建议，玩弄R_LIBS_USER 对我没有用。