Vendor manifest.xml not detected

[Glanda]

I'm trying to port the AOSP master branch to my device. I stuck at the following error:

[  5% 210/3944] build out/target/product/a5y17lte/obj/PACKAGING/check_vintf_all_intermediates/check_vintf_vendor_log
FAILED: out/target/product/a5y17lte/obj/PACKAGING/check_vintf_all_intermediates/check_vintf_vendor_log
/bin/bash -c "( out/host/linux-x86/bin/checkvintf --check-one --dirmap /vendor:out/target/product/a5y17lte/system/vendor --property ro.boot.product.vendor.sku= > out/target/product/a5y17lte/obj/PACKAGING/check_v
intf_all_intermediates/check_vintf_vendor_log 2>&1 ) || ( cat out/target/product/a5y17lte/obj/PACKAGING/check_vintf_all_intermediates/check_vintf_vendor_log && exit 1 )"
checkvintf I 04-10 17:49:39    41    41 check_vintf.cpp:463] Checking vendor manifest.
checkvintf I 04-10 17:49:39    41    41 check_vintf.cpp:122] Sysprop ro.boot.product.vendor.sku=
checkvintf I 04-10 17:49:39    41    41 check_vintf.cpp:74] Fetch 'out/target/product/a5y17lte/system/vendor/etc/vintf/manifest.xml': No such file or directory
checkvintf I 04-10 17:49:39    41    41 check_vintf.cpp:119] Sysprop ro.boot.product.hardware.sku is missing, default to ''
checkvintf I 04-10 17:49:39    41    41 check_vintf.cpp:74] Fetch 'out/target/product/a5y17lte/system/vendor/manifest.xml': No such file or directory
checkvintf W 04-10 17:49:39    41    41 VintfObject.cpp:61] -2: Cannot open out/target/product/a5y17lte/system/vendor/manifest.xml: No such file or directory
checkvintf E 04-10 17:49:39    41    41 check_vintf.cpp:466] Cannot fetch vendor manifest.
checkvintf I 04-10 17:49:39    41    41 check_vintf.cpp:469] Checking vendor matrix.
checkvintf I 04-10 17:49:39    41    41 check_vintf.cpp:74] Fetch 'out/target/product/a5y17lte/system/vendor/etc/vintf/compatibility_matrix.xml': SUCCESS
17:49:40 ninja failed with: exit status 1

#### failed to build some targets (42 seconds) ####

But in my vendor/samsung/a5y17lte/a5y17lte-vendor.mk is the following code:

...
# Vendor Manifest File
PRODUCT_MANIFEST_FILE := vendor/samsung/a5y17lte/manifest.xml
...

I don't know what to do. I've searched a lot but I couldn't find anything in the internet, so I asked here.