Re: [Libguestfs] [PATCH nbdkit v3 2/2] golang: Compile against the local nbdkit build, not installed.

[Eric Blake]

On 4/23/20 2:50 PM, Eric Blake wrote:

PKG_CONFIG_PATH="$(abs_builddir)/server/local$${PKG_CONFIG_PATH:-:$$PKG_CONFIG_PATH}" 
\


Ooops, I typod this one.

unset foo
bar=
blah=set
echo "pre${foo:-:$foo}"
echo "pre${bar:-:$bar}"
echo "pre${bar:-:$blah}"

shows that :- was the wrong operator.  Better is :+.

All four sites need it.

But even then, I'm still getting build failures; and make V=1 shows that 
PKG_CONFIG_PATH is getting set correctly :(


Okay, I found the problem.  $(abs_builddir) is not the same as 
$(abs_top_builddir).


With this incremental on top of your patch, things start working for me:

diff --git i/plugins/golang/Makefile.am w/plugins/golang/Makefile.am
index 10ccea18..74ad4a72 100644
--- i/plugins/golang/Makefile.am
+++ w/plugins/golang/Makefile.am
@@ -66,21 +66,21 @@ noinst_DATA = \
 examples/dump-plugin/nbdkit-godump-plugin.so: \
$(plugin_sources) examples/dump-plugin/dumpplugin.go
cd examples/dump-plugin && \
- 
PKG_CONFIG_PATH="$(abs_builddir)/server/local$${PKG_CONFIG_PATH:-:$$PKG_CONFIG_PATH}" 
\
+ 
PKG_CONFIG_PATH="$(abs_top_builddir)/server/local$${PKG_CONFIG_PATH:+:$$PKG_CONFIG_PATH}" 
\

GOPATH="$(abs_builddir)" \
$(GOLANG) build -o nbdkit-godump-plugin.so -buildmode=c-shared

 examples/minimal/nbdkit-gominimal-plugin.so: \
$(plugin_sources) examples/minimal/minimal.go
cd examples/minimal && \
- 
PKG_CONFIG_PATH="$(abs_builddir)/server/local$${PKG_CONFIG_PATH:-:$$PKG_CONFIG_PATH}" 
\
+ 
PKG_CONFIG_PATH="$(abs_top_builddir)/server/local$${PKG_CONFIG_PATH:+:$$PKG_CONFIG_PATH}" 
\

GOPATH="$(abs_builddir)" \
$(GOLANG) build -o nbdkit-gominimal-plugin.so -buildmode=c-shared

 examples/ramdisk/nbdkit-goramdisk-plugin.so: \
$(plugin_sources) examples/ramdisk/ramdisk.go
cd examples/ramdisk && \
- 
PKG_CONFIG_PATH="$(abs_builddir)/server/local$${PKG_CONFIG_PATH:-:$$PKG_CONFIG_PATH}" 
\
+ 
PKG_CONFIG_PATH="$(abs_top_builddir)/server/local$${PKG_CONFIG_PATH:+:$$PKG_CONFIG_PATH}" 
\

GOPATH="$(abs_builddir)" \
$(GOLANG) build -o nbdkit-goramdisk-plugin.so -buildmode=c-shared

@@ -90,7 +90,7 @@ check_DATA = test/nbdkit-gotest-plugin.so

 test/nbdkit-gotest-plugin.so: $(plugin_sources) test/test.go
cd test && \
- 
PKG_CONFIG_PATH="$(abs_builddir)/server/local$${PKG_CONFIG_PATH:-:$$PKG_CONFIG_PATH}" 
\
+ 
PKG_CONFIG_PATH="$(abs_top_builddir)/server/local$${PKG_CONFIG_PATH:+:$$PKG_CONFIG_PATH}" 
\

GOPATH="$(abs_builddir)" \
$(GOLANG) build -o nbdkit-gotest-plugin.so -buildmode=c-shared



--
Eric Blake, Principal Software Engineer
Red Hat, Inc.   +1-919-301-3226
Virtualization:  qemu.org | libvirt.org

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Re: [Libguestfs] [PATCH nbdkit v3 2/2] golang: Compile against the local nbdkit build, not installed.

[Eric Blake]

On 4/23/20 2:13 PM, Richard W.M. Jones wrote:

Compiling nbdkit from source when an older nbdkit is installed would
fail because certain symbols such as .get_ready are not defined in the
(installed) :

   ../../src/libguestfs.org/nbdkit/nbdkit.go:541:8: plugin.get_ready undefined 
(type _Ctype_struct_nbdkit_plugin has no field or method get_ready)

Of course we should be compiling against the local
include/nbdkit-plugin.h file.

We don't want to modify the *.go files themselves as they might be
copied into other projects.  Instead we can set PKG_CONFIG_PATH to
point to server/local/nbdkit.pc which will return the correct CFLAGS.

Fixes: commit 1ff44288ae1cf95428283e252edd9474c3fe3b55
Thanks: Dan Berrangé, Eric Blake
---



+++ b/plugins/golang/Makefile.am
@@ -66,18 +66,21 @@ noinst_DATA = \
  examples/dump-plugin/nbdkit-godump-plugin.so: \
$(plugin_sources) examples/dump-plugin/dumpplugin.go
cd examples/dump-plugin && \
+   
PKG_CONFIG_PATH="$(abs_builddir)/server/local$${PKG_CONFIG_PATH:-:$$PKG_CONFIG_PATH}"
 \


Ooops, I typod this one.

unset foo
bar=
blah=set
echo "pre${foo:-:$foo}"
echo "pre${bar:-:$bar}"
echo "pre${bar:-:$blah}"

shows that :- was the wrong operator.  Better is :+.

All four sites need it.

But even then, I'm still getting build failures; and make V=1 shows that 
PKG_CONFIG_PATH is getting set correctly :(




--
Eric Blake, Principal Software Engineer
Red Hat, Inc.   +1-919-301-3226
Virtualization:  qemu.org | libvirt.org

___
Libguestfs mailing list
Libguestfs@redhat.com
https://www.redhat.com/mailman/listinfo/libguestfs