Build against the system's HIDAPI instead of the bundled one.

--- open-zwave-1.6-checkout/cpp/build/support.mk	2019-06-16 15:15:34.258331628 +0200
+++ open-zwave-1.6-checkout/cpp/build/support.mk	2019-06-16 15:15:54.698249462 +0200
@@ -86,6 +86,10 @@ endif
 endif
 SED    := sed
 
+# Build against the system's HIDAPI.
+CPPFLAGS += $(shell pkg-config hidapi-libusb --cflags)
+LDFLAGS  += $(shell pkg-config hidapi-libusb --libs)
+
 #determine if we are release or debug Build and set appropriate flags
 ifeq ($(BUILD), release)
 CFLAGS	+= -c $(RELEASE_CFLAGS)
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<tr><td><span title='2021-11-16 14:34:28 +0100'>2021-11-16</span></td><td><a href='/guix/commit/nix/libstore/optimise-store.cc?id=472a0e82a52a3d5d841e1dfad6b13e26082a5750'>daemon: Do not deduplicate files smaller than 8 KiB.</a><span class='msg-avail'>...<span class='msg-tooltip'>Files smaller than 8 KiB typically represent ~70% of the entries in
/gnu/store/.links but only contribute to ~4% of the space savings
afforded by deduplication.

Not considering these files for deduplication speeds up file insertion
in the store and, more importantly, leaves 'removeUnusedLinks' with
fewer entries to traverse, thereby speeding it up proportionally.

Partly fixes &lt;https://issues.guix.gnu.org/24937&gt;.

* config-daemon.ac: Remove symlink hard link check and CAN_LINK_SYMLINK
definition.
* guix/store/deduplication.scm (%deduplication-minimum-size): New
variable.
(deduplicate)[loop]: Do not recurse when FILE's size is below
%DEDUPLICATION-MINIMUM-SIZE.
(dump-port): New procedure.
(dump-file/deduplicate)[hash]: Turn into...
[dump-and-compute-hash]: ... this thunk.
Call 'deduplicate' only when SIZE is greater than
%DEDUPLICATION-MINIMUM-SIZE; otherwise call 'dump-port'.
* nix/libstore/gc.cc (LocalStore::removeUnusedLinks): Drop files where
st.st_size &lt; deduplicationMinSize.
* nix/libstore/local-store.hh (deduplicationMinSize): New declaration.
* nix/libstore/optimise-store.cc (deduplicationMinSize): New variable.
(LocalStore::optimisePath_): Return when PATH is a symlink or smaller
than 'deduplicationMinSize'.
* tests/derivations.scm ("identical files are deduplicated"): Produce
files bigger than %DEDUPLICATION-MINIMUM-SIZE.
* tests/nar.scm ("restore-file-set with directories (signed, valid)"):
Likewise.
* tests/store-deduplication.scm ("deduplicate, below %deduplication-minimum-size"):
New test.
("deduplicate", "deduplicate, ENOSPC"): Produce files bigger than
%DEDUPLICATION-MINIMUM-SIZE.
* tests/store.scm ("substitute, deduplication"): Likewise.
</span></span></td><td>Ludovic Courtès</td></tr>