parallel build issues

[Werner LEMBERG]

[automake 1.16.3
 autoconf 2.71]


Folks,


I have a `Makefile.am` in a `frontend` subdirectory that looks like
the following (abridged).

  bin_PROGRAMS = ttfautohint
  ttfautohint_SOURCES = info.cpp \
                        info.h \
                        main.cpp

  bin_PROGRAMS += ttfautohintGUI
  ttfautohintGUI_SOURCES = ddlineedit.cpp \
                           ddlineedit.h \
                           info.cpp \
                           info.h \
                           main.cpp \
                           maingui.cpp \
                           maingui.h \
                           ttlineedit.cpp \
                           ttlineedit.h
  nodist_ttfautohintGUI_SOURCES = ddlineedit.moc.cpp \
                                  maingui.moc.cpp \
                                  static-plugins.cpp \
                                  ttlineedit.moc.cpp

  ttfautohintGUI_CXXFLAGS = $(QT_CXXFLAGS)
  ttfautohintGUI_LDFLAGS = $(QT_LDFLAGS)
  ttfautohintGUI_CPPFLAGS = $(AM_CPPFLAGS) \
                            $(QT_CPPFLAGS) \
                            -DBUILD_GUI
  ttfautohintGUI_LDADD = $(LDADD) \
                         $(QT_LIBS)

  BUILT_SOURCES = ddlineedit.moc.cpp \
                  maingui.moc.cpp \
                  static-plugins.cpp \
                  ttlineedit.moc.cpp

Running the generated `Makefile` with `make -j12`, I get this:

  ...
  Making all in frontend
  make[2]: Entering directory '.../frontend'
  ...
  make  all-am
  make[3]: Entering directory '.../frontend'
    CXX      info.o
    CXX      main.o
    CXX      ttfautohintGUI-ddlineedit.o
    CXX      ttfautohintGUI-info.o
    CXX      ttfautohintGUI-main.o
    CXX      ttfautohintGUI-maingui.o
    CXX      ttfautohintGUI-ttlineedit.o
  make  ttfautohint
    CXX      ttfautohintGUI-ddlineedit.moc.o
    CXX      ttfautohintGUI-maingui.moc.o
    CXX      ttfautohintGUI-static-plugins.o
    CXX      ttfautohintGUI-ttlineedit.moc.o
  make[4]: Entering directory '.../frontend'
    CXX      info.o
  make  ttfautohintGUI
  make[4]: Entering directory '.../frontend'
    CXXLD    ttfautohintGUI
    CXX      main.o
  mv: cannot stat '.deps/info.Tpo': No such file or directory
  make[4]: *** [Makefile:1401: info.o] Error 1
  make[4]: *** Waiting for unfinished jobs....
    CXXLD    ttfautohint
  make[4]: Leaving directory '.../frontend'
  ...

What am I doing wrong?  I would be glad for any pointers.


    Werner