Libguestfs - Jan 2020 - Re: [PATCH] Link .mli files corresponding to autorgenerated .ml files into builddir

This avoids build failures in separate builds such as this one:

,----
| ocamlfind ocamlc -package str,unix -I . -a guestfs_config.cmo stringMap.cmo
stringSet.cmo std_utils.cmo -o mlstdutils.cma
| ar cr libmlstdutils.a libmlstdutils_a-dummy.o
| ranlib libmlstdutils.a
| File "_none_", line 1:
| Error: Files std_utils.cmo and guestfs_config.cmo
|        make inconsistent assumptions over interface Guestfs_config
| make[4]: *** [Makefile:2580: mlstdutils.cma] Error 2
`----
---
 configure.ac | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/configure.ac b/configure.ac
index 5f8310a640..77a1e986cd 100644
--- a/configure.ac
+++ b/configure.ac
@@ -353,6 +353,10 @@ AC_CONFIG_FILES([Makefile
                  tools/Makefile
                  website/index.html])
 
+AC_CONFIG_LINKS([common/mlstdutils/guestfs_config.mli:common/mlstdutils/guestfs_config.mli
+                 daemon/daemon_config.mli:daemon/daemon_config.mli
+                 v2v/config.mli:v2v/config.mli])
+
 AC_OUTPUT
 
 dnl Produce summary.
-- 
2.25.0.rc2

On Tue, Jan 14, 2020 at 12:04:49AM +0100, Hilko Bengen
wrote:
> This avoids build failures in separate builds such as this one:
> 
> ,----
> | ocamlfind ocamlc -package str,unix -I . -a guestfs_config.cmo
stringMap.cmo stringSet.cmo std_utils.cmo -o mlstdutils.cma
> | ar cr libmlstdutils.a libmlstdutils_a-dummy.o
> | ranlib libmlstdutils.a
> | File "_none_", line 1:
> | Error: Files std_utils.cmo and guestfs_config.cmo
> |        make inconsistent assumptions over interface Guestfs_config
> | make[4]: *** [Makefile:2580: mlstdutils.cma] Error 2
> `----
> ---
>  configure.ac | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/configure.ac b/configure.ac
> index 5f8310a640..77a1e986cd 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -353,6 +353,10 @@ AC_CONFIG_FILES([Makefile
>                   tools/Makefile
>                   website/index.html])
>  
>
+AC_CONFIG_LINKS([common/mlstdutils/guestfs_config.mli:common/mlstdutils/guestfs_config.mli
> +                 daemon/daemon_config.mli:daemon/daemon_config.mli
> +                 v2v/config.mli:v2v/config.mli])
> +
>  AC_OUTPUT
I had to look up what AC_CONFIG_LINKS does :-)

I think this is broadly OK, but I'm fairly sure you don't need the
v2v/ link (since virt-v2v is now a separate project:
https://github.com/libguestfs/virt-v2v).  Maybe this was applied
against a different branch from master?

Rich.

-- 
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Read my programming and virtualization blog: http://rwmj.wordpress.com
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On Tuesday, 14 January 2020 00:04:49 CET Hilko Bengen
wrote:
> This avoids build failures in separate builds such as this one:
> 
> ,----
> | ocamlfind ocamlc -package str,unix -I . -a guestfs_config.cmo
stringMap.cmo stringSet.cmo std_utils.cmo -o mlstdutils.cma
> | ar cr libmlstdutils.a libmlstdutils_a-dummy.o
> | ranlib libmlstdutils.a
> | File "_none_", line 1:
> | Error: Files std_utils.cmo and guestfs_config.cmo
> |        make inconsistent assumptions over interface Guestfs_config
> | make[4]: *** [Makefile:2580: mlstdutils.cma] Error 2
> `----
> ---
>  configure.ac | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/configure.ac b/configure.ac
> index 5f8310a640..77a1e986cd 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -353,6 +353,10 @@ AC_CONFIG_FILES([Makefile
>                   tools/Makefile
>                   website/index.html])
>  
>
+AC_CONFIG_LINKS([common/mlstdutils/guestfs_config.mli:common/mlstdutils/guestfs_config.mli
> +                 daemon/daemon_config.mli:daemon/daemon_config.mli
> +                 v2v/config.mli:v2v/config.mli])
> +
>  AC_OUTPUT
I do not think this is the correct approach.  See my analysis here:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=946594#46

The fixes for this were done upstream recently, see for libguestfs:
https://github.com/libguestfs/libguestfs/commit/323909d92ee681091f15ec2cd9fa1b6bc6379146
https://github.com/libguestfs/libguestfs/commit/4cd801dcff1393f6ffcb81cac9a6dcdb1f007bd2
https://github.com/libguestfs/libguestfs-common/commit/3728b95b880601af95ab2b6b7f1d8110fb5e1fa8
https://github.com/libguestfs/virt-v2v/commit/0e63bae4e84fd2a9752dbf5fa32fcb90631806e3

Plus there were more builddir!=srcdir fixes.

-- 
Pino Toscano

This avoids occasional build failures in builddir != srcdir situations:

,----
| ocamlfind ocamlc -package str,unix -I . -a guestfs_config.cmo stringMap.cmo
stringSet.cmo std_utils.cmo -o mlstdutils.cma
| ar cr libmlstdutils.a libmlstdutils_a-dummy.o
| ranlib libmlstdutils.a
| File "_none_", line 1:
| Error: Files std_utils.cmo and guestfs_config.cmo
|        make inconsistent assumptions over interface Guestfs_config
| make[4]: *** [Makefile:2580: mlstdutils.cma] Error 2
`----

If ocamlc does not find a corresponding .cmi interface file while
building a .cmo object file from .ml source, it will also construct
that .cmi file from the .ml file. This happens in a race with the
build system's explicit .mli -> .cmi build step and therefore may lead
to the result above.
---
 configure.ac | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/configure.ac b/configure.ac
index 5f8310a640..ad0af9cc81 100644
--- a/configure.ac
+++ b/configure.ac
@@ -353,6 +353,9 @@ AC_CONFIG_FILES([Makefile
                  tools/Makefile
                  website/index.html])
 
+AC_CONFIG_LINKS([common/mlstdutils/guestfs_config.mli:common/mlstdutils/guestfs_config.mli
+                 daemon/daemon_config.mli:daemon/daemon_config.mli])
+
 AC_OUTPUT
 
 dnl Produce summary.
-- 
2.25.0.rc2

* Pino Toscano:
> I do not think this is the correct approach.  See my analysis here:
> https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=946594#46
This issue is for a different problem that appeared on some
architectures after I forced *config.ml to be regenerated for the Debian
builds of libguestfs 1.40.2, see
<https://buildd.debian.org/status/logs.php?pkg=libguestfs&ver=1%3A1.40.2-4&suite=sid>.

I have added some observations/analysis to v2 of the patch.

Cheers,
-Hilko