[plt-scheme] 4.2.5.7 compilation error under SGI IRIX 6.

The problem was in the compiler options. "-O3" or "-O2" for some
reason to give an error. Now the “make” going without problems. But
"make install", I received the following error:

mzschemecgc: pre-installing: plot
plot: compiling "src / all" -> "compiled / native / mips-irix /
libplplot.so" ...
compile-extension:
cc-1028 cc: ERROR File = gd_drv.c, Line = 280
  The expression used must have a constant value.

      DrvOpt gd_options [] = (("optimise", DRV_INT, & optimise,
"Optimise PNG palette when possible"),
                                                    ^

cc-1028 cc: ERROR File = gd_drv.c, Line = 281
  The expression used must have a constant value.

                                ("Def_black15", DRV_INT, & black15,
"Define idx 15 as black. If the background is \" whiteish \ "(from
\"-bg \ "option), force index 15 (traditionally white) to be \" black
\ " ")
                                                          ^

cc-1028 cc: ERROR File = gd_drv.c, Line = 282
  The expression used must have a constant value.

                                ("Swp_red15", DRV_INT, & red15, "Swap
index a (usually red) and a (usually white); always done after \"
black15 \ "; quite useful for quick changes to web pages"),
                                                        ^

cc-1028 cc: ERROR File = gd_drv.c, Line = 284
  The expression used must have a constant value.

                                ("8bit", DRV_INT, & palette, "Palette
(8 bit) mode"),
                                                   ^

cc-1028 cc: ERROR File = gd_drv.c, Line = 285
  The expression used must have a constant value.

                                ("24bit", DRV_INT, & truecolour,
"Truecolor (24 bit) mode"),
                                                    ^

cc-1174 cc: WARNING File = gd_drv.c, Line = 261
  The variable "i" was declared but never referenced.

      int i;
          ^

cc-1174 cc: WARNING File = gd_drv.c, Line = 978
  The variable "i" was declared but never referenced.

  int i;
      ^

5 errors detected in the compilation of "gd_drv.c".

The installation will continue, but maybe you can fix it faster way?

After you install this error appeared again, and "make" error occurs.
Binaries are already created, but when I run Drscheme, I can only see
a window with a progress bar, which extends to the end and then it
disappears. And all.