Hi Shane,
On 25 July 2020 at 10:34, Shane McDonald wrote: | This FTBFS is caused by a change in the default | behaviour of GCC from version 9 to version 10. | In version 10, if a global variable is defined in a | header file, and that header file is included by | several files, this results in multiple definitions | of the same variable, and a linker error will be | reported. In previous versions, this error is ignored. | See the "Porting to GCC 10" document | (https://gcc.gnu.org/gcc-10/porting_to.html) for | more details. Yes, I know. I spawned off an R package wrapping DieHarder: RDieHarder. It is on CRAN, and the CRAN maintainer did these gcc-10 tests last December asking us all to update. So I did that in December for RDieHarder: essentially adding a new globals.c and adding 'extern' in front a few dozen variable declarations. And ... I just did the same this morning for DieHarder itself. It is a little messy because the build process is somewhere between a mess and somewhat archaic. This really is code from the mid-2000s and it is showing its age. | To go back to the previous behaviour, it is possible | to use the -fcommon GCC flag. The following patch | makes this change, and results in dieharder | successfully building with GCC 10. I had forgotten about that one too. I may use it for sprng, my other affected package. Or I may let that one die. It was for a very specialised use case for which we now have better tools. DieHarder is a little closer to my heart as I am kinda/sorta a collaborator so I may run with the updated code. Again, really appreciate you looking into it. Cheers, Dirk | diff --git a/debian/rules b/debian/rules | index da08eba..3080547 100755 | --- a/debian/rules | +++ b/debian/rules | @@ -35,7 +35,10 @@ endif | # edd 18 Nov 2006: add -fexceptions, but don't use -O3 as | # 'make check' as gcc hangs in cblas/ after test_ger.c | # edd 27 Dec 2015: add dpkg-buildflags as well | -CFLAGS :=-Wall -pipe -fexceptions -D_REENTRANT $(DEBUGFLAGS) | $(shell dpkg-buildflags --get CFLAGS) | +# shanemcd 24 Jul 2020: add -fcommon for gcc 10's change in default | +# behaviour related to multiple definitions | +# of global variables | +CFLAGS :=-Wall -pipe -fexceptions -fcommon -D_REENTRANT | $(DEBUGFLAGS) $(shell dpkg-buildflags --get CFLAGS) | # edd 29 Sep 2005 alpha needs -mieee with gcc 4.0 | ifeq ($(arch),alpha) | CFLAGS += -mieee | -- | 2.20.1 -- https://dirk.eddelbuettel.com | @eddelbuettel | e...@debian.org
