Use colon (:), not true

[Shushe] / GNUmakefile

diff --git a/GNUmakefile b/GNUmakefile
index d16d76e88da999db79d3172385de93236b31fdfe..89a7cf90bbdc7358a0f29d191d6f0d4ea7ee3b7e 100644 (file)
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -19,6 +19,7 @@ override define makefileinfo
 ║│                                                            │║
 ║│ • awk                                                      │║
 ║│ • cat                                                      │║
+║│ • cd                                                       │║
 ║│ • cksum                                                    │║
 ║│ • cp                                                       │║
 ║│ • date                                                     │║
@@ -99,6 +100,7 @@ endef
 # If these are not installed on your computer, or you need to use a different implementation, you can override the appropriate variable.
 AWK := awk
 CAT := cat
+CD := cd
 CKSUM := cksum
 CP := cp
 DATE := date
@@ -201,12 +203,12 @@ XMLTYPES := application/xml text/xml +xml
 ifdef GIT
 ifneq ($(wildcard $(THISDIR)/.git),)
 # A description of the current git revision of ⛩️📰 书社.
-THISREV := $(shell cd $(THISDIR); $(GIT) describe 2> /dev/null || $(GIT) rev-parse HEAD 2> /dev/null || true)
+THISREV := $(shell $(CD) $(THISDIR); $(GIT) describe 2> /dev/null || $(GIT) rev-parse HEAD 2> /dev/null || :)
 endif
 
 ifneq ($(wildcard .git),)
 # A description of the current git revision of the working directory.
-SRCREV := $(shell $(GIT) describe 2> /dev/null || $(GIT) rev-parse HEAD 2> /dev/null || true)
+SRCREV := $(shell $(GIT) describe 2> /dev/null || $(GIT) rev-parse HEAD 2> /dev/null || :)
 endif
 endif
 
@@ -304,7 +306,7 @@ ifeq ($(MODE),urn:fdc:ladys.computer:20231231:Shu1She4:mode:default)
 # Calling this variable is useful when a given target should be updated whenever its list of prerequisites changes in addition to whenever there is a change to one of its prerequisites.
 #
 # ☡ This variable creates at least one subshell every time it is computed.
-override diffprereqs = $(if $(subst $(shell $(CAT) $(call quote,$(BUILDDIR)/lastprereqs/$1) 2> /dev/null || true),,$2),$2 FORCE$(and $(shell $(call ensuredirectory,$(BUILDDIR)/lastprereqs) && $(PRINTF) '%s\n' $(call quote,$2) > $(BUILDDIR)/lastprereqs/$1),),$2)
+override diffprereqs = $(if $(subst $(shell $(CAT) $(call quote,$(BUILDDIR)/lastprereqs/$1) 2> /dev/null || :),,$2),$2 FORCE$(and $(shell $(call ensuredirectory,$(BUILDDIR)/lastprereqs) && $(PRINTF) '%s\n' $(call quote,$2) > $(BUILDDIR)/lastprereqs/$1),),$2)
 
 # (callable) Escape special characters for use in sed regular expressions.
 override sedesc = $(subst /,[/],$(subst $$,\$$,$(subst *,\*,$(subst .,\.,$(subst [,\[,$(subst ^,\^,$(subst \,\\,$1)))))))
@@ -579,7 +581,7 @@ $(BUILDDIR)/magic.mgc : $(call diffprereqs,magic,$(sort $(call magicfile,$(MAGIC
        $(foreach outdated,$(filter-out $^,$(wildcard $(BUILDDIR)/magic/*)),$(silent)$(RM) $(call quote,$(outdated))$(newline))
        $(call inform,$(PRINTF) '%s\n' 'Compiling new magic…' >&2)
        $(silent)$(call ensuredirectory,$(dir $@))
-       $(silent)cd $(call quote,$(BUILDDIR)) && $(FILE) -C -m $(call quote,$(realpath $(BUILDDIR)/magic))
+       $(silent)$(CD) $(call quote,$(BUILDDIR)) && $(FILE) -C -m $(call quote,$(realpath $(BUILDDIR)/magic))
        $(silent)$(TOUCH) $(call quote,$(BUILDDIR)/.update-types)
 
 # Generate the main parser.
@@ -712,7 +714,7 @@ $(DESTDIR)/% : $(SRC) $(foreach file,$(archivefiles),$(BUILDDIR)/files/$(file))
        $(call inform,$(PRINTF) '%s\n' $(call quote,Archiving </$(NAME)>…) >&2)
        $(silent)$(call ensuredirectory,$(dir $@))
        $(silent)$(RM) -f -R $(call quote,$@)
-       $(silent)cd $(call quote,$(BUILDDIR)/files); if $(call xpath,/*/@*[local-name()="expanded" and namespace-uri()="urn:fdc:ladys.computer:20231231:Shu1She4"],$(abspath $<)); then $(MKDIR) -p $(call quote,$(abspath $@)); $(PRINTF) '%s\n' $(foreach file,$(archivefiles),$(call quote,$(file))) | $(PAX) -r -w $(call quote,$(abspath $@)); else $(PRINTF) '%s\n' $(foreach file,$(archivefiles),$(call quote,$(file))) | $(PAX) -w -x ustar > $(call quote,$(abspath $@)); fi
+       $(silent)$(CD) $(call quote,$(BUILDDIR)/files); if $(call xpath,/*/@*[local-name()="expanded" and namespace-uri()="urn:fdc:ladys.computer:20231231:Shu1She4"],$(abspath $<)); then $(MKDIR) -p $(call quote,$(abspath $@)); $(PRINTF) '%s\n' $(foreach file,$(archivefiles),$(call quote,$(file))) | $(PAX) -r -w $(call quote,$(abspath $@)); else $(PRINTF) '%s\n' $(foreach file,$(archivefiles),$(call quote,$(file))) | $(PAX) -w -x ustar > $(call quote,$(abspath $@)); fi
 
 # ━ § END DEFINED MAKE·FILE MODES ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━