==> dkms install --no-depmod -m akvcam -v 1.0.4 -k 5.7.5-arch1-1
Error! Bad return status for module build on kernel: 5.7.5-arch1-1 (x86_64)
Consult /var/lib/dkms/akvcam/1.0.4/build/make.log for more information.
==> Warning, `dkms install --no-depmod -m akvcam -v 1.0.4 -k 5.7.5-arch1-1' returned 10

DKMS make.log for akvcam-1.0.4 for kernel 5.7.5-arch1-1 (x86_64)
Wed 24 Jun 2020 01:16:31 PM MSK
make -C /usr/lib/modules/5.7.5-arch1-1/build M=/var/lib/dkms/akvcam/1.0.4/build  modules
make[1]: Entering directory '/usr/lib/modules/5.7.5-arch1-1/build'
  CC [M]  /var/lib/dkms/akvcam/1.0.4/build/module.o
  CC [M]  /var/lib/dkms/akvcam/1.0.4/build/attributes.o
  CC [M]  /var/lib/dkms/akvcam/1.0.4/build/buffer.o
  CC [M]  /var/lib/dkms/akvcam/1.0.4/build/buffers.o
  CC [M]  /var/lib/dkms/akvcam/1.0.4/build/controls.o
  CC [M]  /var/lib/dkms/akvcam/1.0.4/build/device.o
  CC [M]  /var/lib/dkms/akvcam/1.0.4/build/driver.o
  CC [M]  /var/lib/dkms/akvcam/1.0.4/build/events.o
  CC [M]  /var/lib/dkms/akvcam/1.0.4/build/file_read.o
  CC [M]  /var/lib/dkms/akvcam/1.0.4/build/format.o
  CC [M]  /var/lib/dkms/akvcam/1.0.4/build/frame.o
/var/lib/dkms/akvcam/1.0.4/build/device.c: In function ‘akvcam_device_new’:
/var/lib/dkms/akvcam/1.0.4/build/device.c:119:28: error: ‘VFL_TYPE_GRABBER’ undeclared (first use in this function); did you mean ‘VFL_TYPE_SUBDEV’?
  119 |     self->vdev->vfl_type = VFL_TYPE_GRABBER;
      |                            ^~~~~~~~~~~~~~~~
      |                            VFL_TYPE_SUBDEV
/var/lib/dkms/akvcam/1.0.4/build/device.c:119:28: note: each undeclared identifier is reported only once for each function it appears in
/var/lib/dkms/akvcam/1.0.4/build/device.c: In function ‘akvcam_device_register’:
/var/lib/dkms/akvcam/1.0.4/build/device.c:185:52: error: ‘VFL_TYPE_GRABBER’ undeclared (first use in this function); did you mean ‘VFL_TYPE_SUBDEV’?
  185 |         result = video_register_device(self->vdev, VFL_TYPE_GRABBER, -1);
      |                                                    ^~~~~~~~~~~~~~~~
      |                                                    VFL_TYPE_SUBDEV
make[2]: *** [scripts/Makefile.build:266: /var/lib/dkms/akvcam/1.0.4/build/device.o] Error 1
make[2]: *** Waiting for unfinished jobs....
  CC [M]  /var/lib/dkms/akvcam/1.0.4/build/global_deleter.o
make[1]: *** [Makefile:1732: /var/lib/dkms/akvcam/1.0.4/build] Error 2
make[1]: Leaving directory '/usr/lib/modules/5.7.5-arch1-1/build'
make: *** [Makefile:42: all] Error 2