title: Makefile won't create and copy file
body: <p>I have the below code for a Makefile. If I run "make" in the command line it creates the xpi file. But when I run the "make install" command it says "Installing in profile folder. Done!" but there is no .xpi to be found and also there isn't one in the path where I need it to be copied.</p>
  
  <p>I've made this work yesterday, but today I lost all the data and needed to start from scrath and it seems I'm missing something. Can't figure out what.</p>
  
  <pre><code>    # The name of the extension.
  extension_name := helloworld@xulschool.com
  
  # The UUID of the extension.
  extension_uuid := helloworld@xulschool.com
  
  # The name of the profile dir where the extension can be installed.
  profile_dir := wiuxd07g.default
  
  # The zip application to be used.
  ZIP := zip
  
  # The target location of the build and build files.
  bin_dir := ../bin
  
  # The target XPI file.
  xpi_file := $(bin_dir)/$(extension_name).xpi
  
  # The type of operating system this make command is running on.
  os_type := $(patsubst darwin%,darwin,$(shell echo $(OSTYPE)))
  
  # The location of the extension profile.
  ifeq ($(os_type), darwin)
    profile_location := \
      ~/Library/Application\ Support/Firefox/Profiles/$(profile_dir)/extensions/\{$(extension_uuid)\}
  else
    ifeq ($(os_type), linux-gnu)
      profile_location := \
        ~/.mozilla/firefox/$(profile_dir)/extensions/\{$(extension_uuid)\}
    else
      profile_location := \
        "$(subst \,\\,$(APPDATA))\\Mozilla\\Firefox\\Profiles\\$(profile_dir)\\extensions\\"
    endif
  endif
  
  # The temporary location where the extension tree will be copied and built.
  build_dir := $(bin_dir)/build
  
  # This builds the extension XPI file.
  .PHONY: all
  all: $(xpi_file)
      @echo
      @echo "Build finished successfully."
      @echo
  
  # This cleans all temporary files and directories created by 'make'.
  .PHONY: clean
  clean:
      @rm -rf $(build_dir)
      @rm -f $(xpi_file)
      @echo "Cleanup is done."
  
  # The sources for the XPI file.
  xpi_built := install.rdf \
               chrome.manifest \
               $(wildcard content/*.js) \
               $(wildcard content/*.xul) \
               $(wildcard content/*.xml) \
               $(wildcard content/*.css) \
               $(wildcard skin/*.css) \
               $(wildcard skin/*.png) \
               $(wildcard locale/*/*.dtd) \
               $(wildcard locale/*/*.properties)
  
  # This builds everything except for the actual XPI, and then it copies it to the
  # specified profile directory, allowing a quick update that requires no install.
  .PHONY: install
  install: $(build_dir) $(xpi_built)
      @echo "Installing in profile folder: $(profile_location)"
      @cp -Rf ../bin/* $(profile_location)
      @echo "Installing in profile folder. Done!"
      @echo
  
  $(xpi_file): $(build_dir) $(xpi_built)
      @echo "Creating XPI file."
      @$(ZIP) $(xpi_file) $(xpi_built)
      @echo "Creating XPI file. Done!"
  
  $(build_dir)/%: %
      @cp -f $&lt; $@
  
  $(build_dir):
      @if [ ! -x $(build_dir) ]; \
    then \
      mkdir $(build_dir); \
    fi
  </code></pre>