BIRD 2.0.2 documentation build failure

[Robert Scheck]

Hello,

I'm trying to build the documentation of BIRD 2.0.2 on Fedora and RHEL/
CentOS 7 which fails like this:

--- snipp ---
+ /usr/bin/make -j4 -C doc
make: Entering directory `/builddir/build/BUILD/bird-2.0.2/doc'
make: Leaving directory `/builddir/build/BUILD/bird-2.0.2/doc'
make: *** No rule to make target `/tools/progdoc', needed by `prog.sgml'. Stop.
--- snapp ---

When I decided to replace "$(srcdir)" in doc/Makefile by ".." it goes
further, but still fails. Replacing "$(objdir)" by "../obj" and finally
replacing "$(doc-srcdir)" by "." leads to the message that bird.sgml has
a loop reference (which leads to an empty bird.sgml). And when removing
this target,

$(o)%.sgml: $(s)%.sgml $(objdir)/.dir-stamp
    cp $< $@

the documentation build even succeeds. In total that's then this diff:

--- snipp ---
--- bird-2.0.2/doc/Makefile       2018-01-16 10:46:06.000000000 +0100
+++ bird-2.0.2/doc/Makefile.doc   2018-11-25 16:38:22.988423717 +0100
@@ -1,7 +1,7 @@
 # Force rebuilds
 .PHONY: progspell docs progdocs userdocs
 
-doc-srcdir := $(shell cd $(s) && pwd)
+doc-srcdir = .
 sgml2 := $(doc-srcdir)/sgml2
 
 docs: progdocs userdocs
@@ -16,11 +16,8 @@
 userdocs: $(o)bird.html $(o)bird.pdf
 progspell: $(o)prog.spell
 
-$(o)prog.sgml: $(srcdir)/tools/progdoc $(objdir)/.dir-stamp
-    $(srcdir)/tools/progdoc $(srcdir) $@
-
-$(o)%.sgml: $(s)%.sgml $(objdir)/.dir-stamp
-    cp $< $@
+$(o)prog.sgml: ../tools/progdoc ../obj/.dir-stamp
+    ../tools/progdoc .. $@
 
 $(o)%.html: $(o)%.sgml
     cd $(dir $@) && $(sgml2)html $(notdir $<)
--- snapp ---

Do you have any pointers? Is this a bug in BIRD or is this a Fedora/RHEL
build system issue?


Regards,
  Robert