performance: 0.911
other: 0.581
graphic: 0.535
files: 0.533
device: 0.527
vnc: 0.503
PID: 0.503
semantic: 0.469
network: 0.461
socket: 0.444
permissions: 0.411
debug: 0.380
boot: 0.281
KVM: 0.235

Missing 'cmp' utility makes build take 10 times as long

I have been doing some work cross compiling qemu for Windows using a minimal Fedora container. Recently I started hitting some timeouts on the CI service and noticed a build of all targets was going over 1 hour.

It seems like the 'cmp' utility from diffutils is used somewhere in the process and if it's missing, either a configure or a make gets run way too many times - I'll try to pull logs from the CI system at some stage soon.

Could a warning or error be added if cmp is missing?

cmp is used in the makefiles. 

And there is some kind of warning during build if it is missing:

/bin/sh: cmp: command not found

But perhaps it should abort the build in this case.

Something like that helps:

diff --git a/Makefile b/Makefile
index 40e4f7677bde..05e029bd99db 100644
--- a/Makefile
+++ b/Makefile
@@ -482,6 +482,7 @@ include $(SRC_PATH)/tests/Makefile.include
 all: $(DOCS) $(if $(BUILD_DOCS),sphinxdocs) $(TOOLS) $(HELPERS-y) recurse-all modules $(vhost-user-json-y)
 
 qemu-version.h: FORCE
+       @type cmp
        $(call quiet-command, \
                 (printf '#define QEMU_PKGVERSION "$(QEMU_PKGVERSION)"\n'; \
                printf '#define QEMU_FULL_VERSION "$(FULL_VERSION)"\n'; \


Does this problem still persist with the latest version of QEMU (since we switched the build system mostly to meson now)?

[Expired for QEMU because there has been no activity for 60 days.]