r-cran.mk: Allow R package source tree as a subtree of larger project

[Steffen Möller <steffen_moeller@gmx.de>]

Hello,

The Apache arrow source tree has a subdirectory "r" in which is residing what constitutes the r-cran-arrow source tree. I want to generate the r-cran-arrow package from the very same source tree as arrow itself, but ran into some lintian errors

E: r-cran-arrow: missing-dependency-on-libc needed by usr/lib/R/site-library/arrow/libs/arrow.so
E: r-cran-arrow: requires-r-api

that I thought I could circumvent by properly using r-cran.mk.

That parses the DESCRIPTION file which should now be r/DESCRIPTION and maybe if the variables are already set then those should not be overridden. Here a first suggestion for a patch to r-cran.mk with a request for further discussion - and if you happen to know how to manually overcome those lintian errors then I would obviously also appreciate that :-)


--- /usr/share/dh-r/r-cran.mk.orig      2025-09-11 13:21:18.681628060 +0100
+++ /usr/share/dh-r/r-cran.mk   2025-09-11 13:26:57.445627215 +0100
@@ -6,15 +6,16 @@

 include /usr/share/dpkg/default.mk

-debRreposname  := $(shell echo $(DEB_SOURCE) | sed 's/r-\([a-z]\+\)-.*/\1/')
+origRsubdir     ?= "./"
+debRreposname  ?= $(shell echo $(DEB_SOURCE) | sed 's/r-\([a-z]\+\)-.*/\1/')
 # apply it to the upstream meta-info file DESCRIPTION (seems to be some helpful trick to keep the quoting)
-cranNameOrig    := $(shell awk '/^(Package|Bundle):/ {print $$2 }' DESCRIPTION)
+cranNameOrig    ?= $(shell awk '/^(Package|Bundle):/ {print $$2 }' ${origRsubdir}DESCRIPTION)
 # generate a lc version
-cranName       := $(shell echo "$(cranNameOrig)" | tr A-Z a-z)
-package                := r-$(debRreposname)-$(cranName)
+cranName       ?= $(shell echo "$(cranNameOrig)" | tr A-Z a-z)
+package                ?= r-$(debRreposname)-$(cranName)

 ## awk command to extract word after Priority
-priority        := $(shell awk '/^Priority:/ {print tolower($$2) }' DESCRIPTION)
+priority        := $(shell awk '/^Priority:/ {print tolower($$2) }' ${origRsubdir}DESCRIPTION)

 ifeq ($(priority),recommended)
   debRdir      := usr/lib/R/library


I think I am not subscribed to this list, please kindly CC me.

Best,
Steffen