title: What is the difference between "mv" and "-mv" shell commands in a makefile?
body: <p>I have stumbled upon a person changing <code>mv</code> command to <code>-mv</code> within a makefile target. What is the difference?</p>
  
  <pre><code>%/install-stamp:                                                                                                           
          dh_testdir                                                                                                         
          dh_testroot                                                                                                        
          dh_prep -p$(subst _,-,$(a))-toolchain                                                                                       
          cp -rl $(r) debian/$(subst _,-,$(a))-toolchain                                                                     
          -mv debian/$(subst _,-,$(a))-toolchain/usr/bin/libgcc_s_sjlj-1.dll debian/$(subst _,-,$(a))-toolchain/usr/$(subst \
  _,-,$(a))/bin                                                                                                              
          -mv debian/$(subst _,-,$(a))-toolchain/usr/lib/libiberty.a debian/$(subst _,-,$(a))-toolchain/usr/$(subst _,-,$(a)\
  )/lib                                                                                                                      
          rm -f debian/$(subst _,-,$(a))-toolchain/usr/share/man/man1/dllwrap*                                               
          rm -f debian/$(subst _,-,$(a))-toolchain/usr/share/man/man7/fsf-funding*                                           
          rm -f debian/$(subst _,-,$(a))-toolchain/usr/share/man/man7/gfdl*                                                  
          rm -f debian/$(subst _,-,$(a))-toolchain/usr/share/man/man7/gpl*                                                   
          touch $(@)       
  </code></pre>