r markdown-需要Pandoc 1.12.3或更高版本，但未找到（R Shiny）

我从托管在服务器上的我的应用程序闪亮生成pdf报告时遇到问题。

该应用程序运行正常，但是当我按下按钮下载报告时，出现此错误：

pandoc version 1.12.3 or higher is required and was not found.
问题是，如果我键入$PATH，则会得到：

pandoc 1.12.3.3
Compiled with texmath 0.6.6, highlighting-kate 0.5.6.1.
Syntax highlighting is supported for the following languages:
actionscript, ada, apache, asn1, asp, awk, bash, bibtex, boo, c, changelog,
clojure, cmake, coffee, coldfusion, commonlisp, cpp, cs, css, curry, d,
diff, djangotemplate, doxygen, doxygenlua, dtd, eiffel, email, erlang,
fortran, fsharp, gnuassembler, go, haskell, haxe, html, ini, java, javadoc,
javascript, json, jsp, julia, latex, lex, literatecurry, literatehaskell,
lua, makefile, mandoc, markdown, matlab, maxima, metafont, mips, modelines,
modula2, modula3, monobasic, nasm, noweb, objectivec, objectivecpp, ocaml,
octave, pascal, perl, php, pike, postscript, prolog, python, r,
relaxngcompact, restructuredtext, rhtml, roff, ruby, rust, scala, scheme,
sci, sed, sgml, sql, sqlmysql, sqlpostgresql, tcl, texinfo, verilog, vhdl,
xml, xorg, xslt, xul, yacc, yaml
Default user data directory: /home/daniele/.pandoc
Copyright (C) 2006-2013 John MacFarlane
Web: http://johnmacfarlane.net/pandoc
This is free software; see the source for copying conditions. There is no
warranty, not even for merchantability or fitness for a particular purpose.
所以我想我有合适的版本。 还安装了TexLive，路径在$PATH中。

服务器

library(shiny)
library(drsmooth)
library(shinyBS)
library(knitr)
library(xtable)
library(rmarkdown)

shinyServer(function(input, output,session) {

output$downloadReport <- downloadHandler(
filename = function() {
paste(‘report’, sep = ‘.’,’pdf’)
},

content = function(file) {
src <- normalizePath(‘report.Rmd’)

# temporarily switch to the temp dir, in case you do not have write
# permission to the current working directory
owd <- setwd(tempdir())
on.exit(setwd(owd))
file.copy(src, ‘report.Rmd’)

library(rmarkdown)
out <- render(‘report.Rmd’)
file.rename(out, file)
})

output$tb <- renderUI({
p(h4(“Report”)),
“Dowload a the report of your analysis in a pdf format”,
tags$br(),downloadButton(‘downloadReport’,label=”Download report”),
tags$em(“This option will be available soon”)
})
})
* report.Rmd *不包含任何类型的计算，仅是文本。pdf生成可以在我的本地版本（MacOS）上正常运行，但不能在服务器上运行。

预先谢谢您，如果需要，我在这里提供其他信息。