[Rd] R build fails during make when configured with "--with-x=no" (PR#13665)

[jeet at ku.edu]

Full_Name: Jeet Sukumaran
Version: 2.9.0
OS: OS X / Rocks 5.1 
Submission from: (NULL) (66.45.136.241)


If R is configured using the "--with=x=no" option, then the make fails with the
following error:

make[4]: Entering directory
`/home/jeet/Scratch/r-build/on-frontend/R-2.9.0/src/modules/vfonts'
gcc -std=gnu99 -I. -I../../../src/include -I../../../src/include
-I/usr/local/include -DHAVE_CONFIG_H   -fpic  -g -O2 -c g_alab_her.c -o
g_alab_her.o
gcc -std=gnu99 -I. -I../../../src/include -I../../../src/include
-I/usr/local/include -DHAVE_CONFIG_H   -fpic  -g -O2 -c g_cntrlify.c -o
g_cntrlify.o
gcc -std=gnu99 -I. -I../../../src/include -I../../../src/include
-I/usr/local/include -DHAVE_CONFIG_H   -fpic  -g -O2 -c g_fontdb.c -o
g_fontdb.o
gcc -std=gnu99 -I. -I../../../src/include -I../../../src/include
-I/usr/local/include -DHAVE_CONFIG_H   -fpic  -g -O2 -c g_her_glyph.c -o
g_her_glyph.o
gcc -std=gnu99 -shared -L/usr/local/lib64 -o vfonts.so g_alab_her.o g_cntrlify.o
g_fontdb.o g_her_glyph.o  -lm 
make[5]: Entering directory
`/home/jeet/Scratch/r-build/on-frontend/R-2.9.0/src/modules/vfonts'
make[5]: Leaving directory
`/home/jeet/Scratch/r-build/on-frontend/R-2.9.0/src/modules/vfonts'
make[4]: Leaving directory
`/home/jeet/Scratch/r-build/on-frontend/R-2.9.0/src/modules/vfonts'
make[3]: Leaving directory
`/home/jeet/Scratch/r-build/on-frontend/R-2.9.0/src/modules/vfonts'
make[3]: Entering directory `/home/jeet'
make[3]: *** No rule to make target `R'.  Stop.
make[3]: Leaving directory `/home/jeet'
make[2]: *** [R] Error 1
make[2]: Leaving directory
`/home/jeet/Scratch/r-build/on-frontend/R-2.9.0/src/modules'
make[1]: *** [R] Error 1
make[1]: Leaving directory `/home/jeet/Scratch/r-build/on-frontend/R-2.9.0/src'
make: *** [R] Error 1

The problem appears to be with the "src/modules/Makefile". Specfically, lines
26-29:

	@for d in "$(R_MODULES)"; do \
	  (cd $${d} && $(MAKE) $@) || exit 1; \
	done

Here, R_MODULES is blank, resulting in the "cd" command transferring to the
user's home directory, where, of course, no Makefile is found resulting in the
error above.

Work-around appears to be to simply disable loop if R_MODULES is empty.