Metapost btex etex problem

metapost: Unable to make mpx file

ref

• 要被metapost的Unable to make mpx file 整崩溃了。 - ctex.org
• 以下为什么不能编绎？ - chinatex.org
• [metapost] Metapost btex etex problem - tug.org
• [metapost] Unable to make mpx file. Btex and etex issue - tug.org
• "! Unable to make mpx file." - G+
• tex.stackexchange 上搜 Unable to read mpx file啥都没有
  搜Unable to make mpx file有三个问题....上面都是make
  以下是唯一一个与Unable to read mpx file相关的,是源码
• 巨坑的源码 Diff of /trunk/source/texk/web2c/mplibdir/mp.w

问题简述

mpost 编译不加任何头的mp 文件可以正常生成mps 但从上一级目录编译就不行

正常情况:

I:\Desktop\Translation\TeX-doc\Metapost\Metapost-doc-CHS\source-manual>cd mp

I:\Desktop\Translation\TeX-doc\Metapost\Metapost-doc-CHS\source-manual\mp>mpost mpgraph.mp
This is MetaPost, version 1.9991 (TeX Live 2016/W32TeX) (kpathsea version 6.2.2)
(f:/study/texlive/2016/texmf-dist/metapost/base/mpost.mp
(f:/study/texlive/2016/texmf-dist/metapost/base/plain.mp
Preloading the plain mem file, version 1.005) ) (./mpgraph.mp
(f:/study/texlive/2016/texmf-dist/metapost/base/graph.mp
(f:/study/texlive/2016/texmf-dist/metapost/base/marith.mp
(f:/study/texlive/2016/texmf-dist/metapost/base/string.mp))
(f:/study/texlive/2016/texmf-dist/metapost/base/format.mp
(f:/study/texlive/2016/texmf-dist/metapost/base/string.mp)
(f:/study/texlive/2016/texmf-dist/metapost/base/texnum.mp))) [1] [2] [3] [4]
[5] [6] (f:/study/texlive/2016/texmf-dist/metapost/base/sarith.mp) [7] [8]
[9] [10] [11] )
11 output files written: mpgraph-1.mps .. mpgraph-11.mps
Transcript written on mpgraph.log.

改为上一级目录：

I:\Desktop\Translation\TeX-doc\Metapost\Metapost-doc-CHS\source-manual\mp>mpost --debug ./mp/mpgraph.mp
This is MetaPost, version 1.9991 (TeX Live 2016/W32TeX) (kpathsea version 6.2.2)
(f:/study/texlive/2016/texmf-dist/metapost/base/mpost.mp
(f:/study/texlive/2016/texmf-dist/metapost/base/plain.mp
Preloading the plain mem file, version 1.005) ) (./mpgraph.mp
(f:/study/texlive/2016/texmf-dist/metapost/base/graph.mp
(f:/study/texlive/2016/texmf-dist/metapost/base/marith.mp
(f:/study/texlive/2016/texmf-dist/metapost/base/string.mp))
(f:/study/texlive/2016/texmf-dist/metapost/base/format.mp
(f:/study/texlive/2016/texmf-dist/metapost/base/string.mp)
(f:/study/texlive/2016/texmf-dist/metapost/base/texnum.mp
>> texnum.mp
>> texnum.mpx
! ! Unable to read mpx file.
l.17 init_numbers(btex
                      $-$etex, btex$1$etex, btex${\times}10$etex,
Transcript written on mpgraph.log.

I:\Desktop\Translation\TeX-doc\Metapost\Metapost-doc-CHS\source-manual\mp>