further toplevel logging tweaks

Essentially some more polishing:
- image path extracted from downstream build log;
- extended error/warning regexp a bit so those with
  color grep options get even prettier output.

Notes:
- "1024" a magic number (briefly explained when introduced)
  moved to a sort of variable;
- "100 lines" for tail(1) is a rule-of-thumb taking into account
  typical amount of hasher/mkimage exhaust given GLOBAL_VERBOSE.

image.in/Makefile

@@ -33,7 +33,7 @@ $(IMAGEDIR):
 
 postprocess:
 	@OUTPATH="$(IMAGEDIR)/$(IMAGE_OUTFILE)"; \
-	echo "** image: $(IMAGE_OUTFILE)" && \
+	echo "** image: $$OUTPATH" >&2 && \
 	ln -sf "$(IMAGE_OUTFILE)" "$(IMAGEDIR)/$(IMAGE_FILE)" && \
 	ln -sf "$(IMAGE_FILE)" "$(IMAGEDIR)/$(LINKPREFIX).$(IMAGE_TYPE)"; \
 	ln -sf "$${OUTPATH#`pwd`/}" "$(IMAGE_FILE)"; \

lib/build.mk

@@ -11,6 +11,9 @@ ifdef NICE
 START := nice $(shell ionice -c3 echo "ionice -c3" 2>/dev/null)
 endif
 
+# in kilobytes (a kilometer is 1024 meters, you know)
+LOWSPACE = 1024
+
 # it's also nice to know how long and much it takes
 START += time -f "%E %PCPU %Mk"
 
@@ -34,15 +37,16 @@ build: profile/populate
 		fi; \
 	fi
 	@if $(START) $(MAKE) -C $(BUILDDIR)/ $(LOG); then \
-		echo "$(TIME) build done (`tail -1 $(BUILDLOG) | cut -f1 -d. \
-			|| echo "no log"`)"; \
+		echo "$(TIME) done (`tail -1 $(BUILDLOG) | cut -f1 -d.`)"; \
+		tail -200 "$(BUILDLOG)" \
+		| grep --color=always '^\*\* image: .*' $(SHORTEN) ||:; \
 	else \
-		echo "$(TIME) build failed, see log: $(BUILDLOG)" $(SHORTEN); \
+		echo "$(TIME) failed, see log: $(BUILDLOG)" $(SHORTEN); \
 		if [ -z "$(DEBUG)" ]; then \
 			echo "$(TIME) (you might want to re-run with DEBUG=1)"; \
 		fi; \
-		tail -100 "$(BUILDLOG)" | egrep "^E:|[Ee]rror|[Ww]arning"; \
-		df -P $(BUILDDIR) | awk 'END { if ($$4 < 1024) \
+		tail -200 "$(BUILDLOG)" | egrep "^(E:|[Ee]rror|[Ww]arning).*"; \
+		df -P $(BUILDDIR) | awk 'END { if ($$4 < $(LOWSPACE)) \
 			{ print "NB: low space on "$$6" ("$$5" used)"}}'; \
 	fi
 	@if [ -n "$(BELL)" ]; then echo -ne '\a' >&2; fi

lib/profile.mk

@@ -71,7 +71,8 @@ profile/init: distclean
 	fi $(SHORTEN)
 
 profile/bare: profile/init
-	@echo "$(TIME) preparing distro config$${DEBUG:+: see $(CONFIG)}" \
+	@NOTE="$${GLOBAL_VERBOSE:+: $(CONFIG)}"; \
+		echo "$(TIME) preparing distro config$$NOTE" \
 		$(SHORTEN)
 	@$(call try,MKIMAGE_PREFIX,/usr/share/mkimage)
 	@$(call try,GLOBAL_VERBOSE,)