$ nix-build -A neovim
these derivations will be built:
  /nix/store/4wx9xn4zysrqkia9n55vb46jfxpi6a99-luajit-2.1.0-beta3-luv-1.30.0-0.drv
  /nix/store/3adbwmw56z7qgjqzm7vw7kqxr5hmflw6-neovim-unwrapped-0.4.3.drv
  /nix/store/3yi4yxsws4g3qyjjphhsbx1hlicwnf77-neovim-0.4.3.drv
building '/nix/store/4wx9xn4zysrqkia9n55vb46jfxpi6a99-luajit-2.1.0-beta3-luv-1.30.0-0.drv'...
unpacking sources
unpacking source archive /nix/store/iqsk16lkjsixwmrq9w3b6szh4nm3mpcf-luv-1.30.0-0.src.rock

Done. You may now enter directory
luv-1.30.0-0/luv-1.30.0-0
and type 'luarocks make' to build.
source root is ./luv-1.30.0-0/luv-1.30.0-0
setting SOURCE_DATE_EPOCH to timestamp 1561806879 of file ./luv-1.30.0-0/luv-1.30.0-0/src/work.c
patching sources
configuring
building
patching script interpreter paths in .
./deps/lua-compat-5.3/tests/test.lua: interpreter directive changed from "/usr/bin/env lua" to "/nix/store/vy5x75rdxcr8g4jk2xv31zvd9mfcyb6v-luajit-2.1.0-beta3/bin/lua"
installing

luv 1.30.0-0 depends on lua >= 5.1 (5.1-1 provided by VM)
Warning: unmatched variable LUA_LIBDIR
-- The C compiler identification is GNU 9.2.0
-- The ASM compiler identification is GNU
-- Found assembler: /nix/store/3fncfqvh6mz5x2my2s3aiqa9w0rmvcy4-gcc-wrapper-9.2.0/bin/gcc
-- Check for working C compiler: /nix/store/3fncfqvh6mz5x2my2s3aiqa9w0rmvcy4-gcc-wrapper-9.2.0/bin/gcc
-- Check for working C compiler: /nix/store/3fncfqvh6mz5x2my2s3aiqa9w0rmvcy4-gcc-wrapper-9.2.0/bin/gcc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Found LIBUV: /nix/store/f711zxf89ga3in4gph12jclqdryc5n34-libuv-1.34.2/lib/libuv.so
-- Lua: using information from luarocks
-- LUA_LIBDIR:
-- LUA_INCDIR: /nix/store/vy5x75rdxcr8g4jk2xv31zvd9mfcyb6v-luajit-2.1.0-beta3/include/luajit-2.1
-- LUA: /nix/store/vy5x75rdxcr8g4jk2xv31zvd9mfcyb6v-luajit-2.1.0-beta3/bin/luajit
-- Lua library: LUA_LIBRARIES-NOTFOUND
-- Configuring done
-- Generating done
-- Build files have been written to: /build/luv-1.30.0-0/luv-1.30.0-0/build.luarocks
Scanning dependencies of target luv
[ 50%] Building C object CMakeFiles/luv.dir/src/luv.c.o
[100%] Linking C shared library libluv.so
[100%] Built target luv
[100%] Built target luv
Install the project...
-- Install configuration: ""
-- Installing: /nix/store/d29kmg3nijdi4s3wb0k68kvfz3nq3frf-luajit-2.1.0-beta3-luv-1.30.0-0/luv-1.30.0-0-rocks/luv/1.30.0-0/lib/libluv.so.1.30.0
-- Installing: /nix/store/d29kmg3nijdi4s3wb0k68kvfz3nq3frf-luajit-2.1.0-beta3-luv-1.30.0-0/luv-1.30.0-0-rocks/luv/1.30.0-0/lib/libluv.so.1
-- Installing: /nix/store/d29kmg3nijdi4s3wb0k68kvfz3nq3frf-luajit-2.1.0-beta3-luv-1.30.0-0/luv-1.30.0-0-rocks/luv/1.30.0-0/lib/libluv.so
-- Installing: /nix/store/d29kmg3nijdi4s3wb0k68kvfz3nq3frf-luajit-2.1.0-beta3-luv-1.30.0-0/include/luv/luv.h
-- Installing: /nix/store/d29kmg3nijdi4s3wb0k68kvfz3nq3frf-luajit-2.1.0-beta3-luv-1.30.0-0/include/luv/util.h
-- Installing: /nix/store/d29kmg3nijdi4s3wb0k68kvfz3nq3frf-luajit-2.1.0-beta3-luv-1.30.0-0/include/luv/lhandle.h
-- Installing: /nix/store/d29kmg3nijdi4s3wb0k68kvfz3nq3frf-luajit-2.1.0-beta3-luv-1.30.0-0/include/luv/lreq.h
cp: cannot stat '/nix/store/d29kmg3nijdi4s3wb0k68kvfz3nq3frf-luajit-2.1.0-beta3-luv-1.30.0-0/luv-1.30.0-0-rocks/luv/1.30.0-0/lib/libluv.so': No such file or directory

Error: Failed copying /nix/store/d29kmg3nijdi4s3wb0k68kvfz3nq3frf-luajit-2.1.0-beta3-luv-1.30.0-0/luv-1.30.0-0-rocks/luv/1.30.0-0/lib/libluv.so to /nix/store/d29kmg3nijdi4s3wb0k68kvfz3nq3frf-luajit-2.1.0-beta3-luv-1.30.0-0/lib/lua/5.1/libluv.so
builder for '/nix/store/4wx9xn4zysrqkia9n55vb46jfxpi6a99-luajit-2.1.0-beta3-luv-1.30.0-0.drv' failed with exit code 1
cannot build derivation '/nix/store/3adbwmw56z7qgjqzm7vw7kqxr5hmflw6-neovim-unwrapped-0.4.3.drv': 1 dependencies couldn't be built
cannot build derivation '/nix/store/3yi4yxsws4g3qyjjphhsbx1hlicwnf77-neovim-0.4.3.drv': 1 dependencies couldn't be built
error: build of '/nix/store/3yi4yxsws4g3qyjjphhsbx1hlicwnf77-neovim-0.4.3.drv' failed