- reverted the earlier change to restore indirection through

InstallPrefix, since it didn't and can't play well with the
  generated config.h.  Instead removed InstallPrefix entirely so
  it isn't an attractive hazzard.
    configure, makefiles/Mf-install.in

original commit: 21c8b40bbe4431795824e48042112820872a1fe5

LOG

@@ -1132,3 +1132,8 @@
   we're not presently generating empty vectors (representing empty
   groups), but the fasl format permits them.
     7.ss
+- reverted the earlier change to restore indirection through
+  InstallPrefix, since it didn't and can't play well with the
+  generated config.h.  Instead removed InstallPrefix entirely so
+  it isn't an attractive hazzard.
+    configure, makefiles/Mf-install.in

configure

@@ -249,15 +249,15 @@ if [ "$w" = "" ] ; then
 fi
 
 if [ "$installbin" = "" ] ; then
-  installbin='${InstallPrefix}/bin'
+  installbin=$installprefix/bin
 fi
 
 if [ "$installlib" = "" ] ; then
-  installlib='${InstallPrefix}/lib'
+  installlib=$installprefix/lib
 fi
 
 if [ "$installman" = "" ] ; then
-  installman='${InstallPrefix}'/$installmansuffix
+  installman=$installprefix/$installmansuffix
 fi
 
 if [ "$disablex11" = "no" ] ; then
@@ -361,7 +361,6 @@ sed -e 's/$(m)/'$m'/g'\
     makefiles/Mf-boot.in > $w/Mf-boot
 
 sed -e "s;^m=none\$;m=$m;"\
-    -e "s;^InstallPrefix=.*\$;InstallPrefix=$installprefix;"\
     -e "s;^InstallBin=.*\$;InstallBin=$installbin;"\
     -e "s;^InstallLib=.*\$;InstallLib=$installlib;"\
     -e "s;^InstallMan=.*\$;InstallMan=$installman/man1;"\

makefiles/Mf-install.in

@@ -22,18 +22,14 @@ m=none
 # The following variables determine where the executables, boot files,
 # example programs, and manual pages are installed.
 
-# InstallPrefix is the final destination base and will be reflected
-# in the generated manual page
-InstallPrefix=/usr
-
 # executable directory
-InstallBin=${InstallPrefix}/bin
+InstallBin=/usr/bin
 
 # library directory
-InstallLib=${InstallPrefix}/lib
+InstallLib=/usr/lib
 
 # man page directory
-InstallMan=${InstallPrefix}/man/man1
+InstallMan=/usr/man/man1
 
 # installation owner
 InstallOwner=
@@ -41,7 +37,8 @@ InstallOwner=
 # installation group
 InstallGroup=
 
-# Files are actually installed at ${TempRoot}${InstallPrefix}
+# Files are actually installed at ${TempRoot}${InstallBin},
+# ${TempRoot}${InstallLib}, and ${TempRoot}${InstallMan}.
 # This useful for testing the install process and for building
 # installation scripts
 TempRoot=