Module failed to build again after next kernel update. Seems MAKE and CLEAN instructions aren't required for DKMS. This patch fix issue:

diff --git a/PKGBUILD b/PKGBUILD
index 3755fb1..21f23cb 100644
--- a/PKGBUILD
+++ b/PKGBUILD
@@ -13,7 +13,7 @@ url='https://github.com/gmarco/i2c-ch341'
 source=("git://github.com/gmarco/i2c-ch341.git"
         'dkms.conf.in')
 md5sums=('SKIP'
-         '4d3cb44f5d9d97cb4b72a9e2470789e2')
+         '2ecaebde0d8628a26932eb5ec21af6a8')

 package() {
   cd ${srcdir}/i2c-ch341
diff --git a/dkms.conf.in b/dkms.conf.in
index 9eace61..8728b17 100644
--- a/dkms.conf.in
+++ b/dkms.conf.in
@@ -1,9 +1,6 @@
 PACKAGE_NAME="i2c-ch341"
 PACKAGE_VERSION="#MODULE_VERSION#"

-MAKE[0]="make KERNEL_DIR=${kernel_source_dir} all"
-CLEAN="make KERNEL_DIR=${kernel_source_dir} clean"
-
 BUILT_MODULE_NAME[0]="i2c-ch341"
 DEST_MODULE_LOCATION[0]="/extramodules"
 AUTOINSTALL="yes"

same error as @rootpeer with 5.10 and 5.12. Would be very thankful to @sergej if he could have a look at this :)

Cannot build on 5.9.8:

cat /var/lib/dkms/i2c-ch341/20190628/build/make.log 
DKMS make.log for i2c-ch341-20190628 for kernel 5.9.8-arch1-1 (x86_64)
Wed 18 Nov 14:31:45 EET 2020
make: Entering directory '/usr/lib/modules/5.9.8-arch1-1/build'
make[1]: Nothing to be done for 'objtool'.
make[1]: *** No rule to make target 'bpf/resolve_btfids'.  Stop.
make: *** [Makefile:1885: tools/bpf/resolve_btfids] Error 2
make: *** Waiting for unfinished jobs....
scripts/Makefile.build:44: arch/x86/entry/syscalls/Makefile: No such file or directory
make[1]: *** No rule to make target 'arch/x86/entry/syscalls/Makefile'.  Stop.
make: *** [arch/x86/Makefile:219: archheaders] Error 2
make: Leaving directory '/usr/lib/modules/5.9.8-arch1-1/build'

Makefile from driver sources can't build the module for newly installed kernel (different from currently running).

Using

MAKE[0]="make -C /lib/modules/${kernelver}/build M=${dkms_tree}/${PACKAGE_NAME}/${PACKAGE_VERSION}/build modules"

CLEAN="make -C /lib/modules/${kernelver}/build M=${dkms_tree}/${PACKAGE_NAME} /${PACKAGE_VERSION}/build clean"

instead of

MAKE[0]="make KVERSION=$kernelver BUILD_KERNEL=$kernelver"

CLEAN="make clean"

in dkms.conf.in works for me.