libisc.so: undefined reference to uv_os_getenv on Stretch

Job #2492167 failed for 4e8d1207 on Debian Stretch with libuv 1.9.1, which does not have uv_os_getenv:

libtool: link: gcc -Wall -Wextra -Wwrite-strings -Wpointer-arith -Wno-missing-field-initializers -Wformat -Wshadow -Werror=implicit-function-declaration -Werror=missing-prototypes -Werror=format-security -Werror=parentheses -Werror=implicit -Werror=strict-prototypes -Werror=vla -fno-strict-aliasing -fno-delete-null-pointer-checks -fdiagnostics-show-option -Werror -fno-omit-frame-pointer -fno-optimize-sibling-calls -O1 -g -Wall -Wextra -O2 -pthread -Wl,--export-dynamic -o .libs/named builtin.o config.o control.o controlconf.o dlz_dlopen_driver.o fuzz.o log.o logconf.o main.o os.o server.o statschannel.o tkeyconf.o transportconf.o tsigconf.o zoneconf.o geoip.o xsl.o  ../../lib/isc/.libs/libisc.so ../../lib/dns/.libs/libdns.so ../../lib/ns/.libs/libns.so ../../lib/isccc/.libs/libisccc.so ../../lib/isccfg/.libs/libisccfg.so ../../lib/bind9/.libs/libbind9.so -lssl -lcrypto -lcap -llmdb -lmaxminddb -lfstrm -lprotobuf-c -luv -lrt -lnsl -ldl -lxml2 -lz -ljson-c -lnghttp2 -lpthread -pthread
../../lib/isc/.libs/libisc.so: undefined reference to `uv_os_getenv'
collect2: error: ld returned 1 exit status
Makefile:625: recipe for target 'named' failed

The culprit seems to be b4381269 (merged yesterday). When reverted, main builds again.