Can't build falco offline
Author: k0steCreated Aug 4, 2026Updated Sep 9, 2026
Labelskind/bug
The Problem
When I try to build falco without internet - cmake fails
How-to reproduce
cmake -B "skeleton-build" -S "falco-0.44.1" \
-Wno-author \
-DFETCHCONTENT_FULLY_DISCONNECTED=On \
-DDRIVER_SOURCE_DIR="${srcdir}/libs-10.2.0-driver" \
-DFALCOSECURITY_LIBS_SOURCE_DIR="${srcdir}/libs-0.25.4" \
-DUSE_BUNDLED_DEPS=Off \
-DBUILD_DRIVER=Off \
-DBUILD_FALCO_MODERN_BPF=On \
-DUSE_BUNDLED_CPPHTTPLIB=Off \
-DUSE_BUNDLED_DRIVER=Off \
-DUSE_BUNDLED_JSONCPP=Off \
-DUSE_BUNDLED_LIBBPF=Off \
-DUSE_BUNDLED_LIBELF=Off \
-DUSE_BUNDLED_MODERN_BPF=Off \
-DUSE_BUNDLED_NLOHMANN_JSON=Off \
-DUSE_BUNDLED_OPENSSL=Off \
-DUSE_BUNDLED_RE2=Off \
-DUSE_BUNDLED_TBB=Off \
-DUSE_BUNDLED_UTHASH=Off \
-DUSE_BUNDLED_VALIJSON=Off \
-DUSE_BUNDLED_YAMLCPP=Off \
-DUSE_BUNDLED_ZLIB=Off \
-DFALCO_VERSION="0.44.1"
cmake --build "skeleton-build" --target "ProbeSkeleton"Expected Results
cmake used already downloaded and unpacked tarballs
Actual Results
-- The C compiler identification is GNU 16.1.1
-- The CXX compiler identification is GNU 16.1.1
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: /usr/bin/cc - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/c++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Build type: release
-- Using local version of falcosecurity/libs: '/srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4'
-- Looking for strlcpy
-- Looking for strlcpy - found
-- Existing strlcpy and strlcat found, will *not* use local definition by setting -DHAVE_STRLCPY and -DHAVE_STRLCAT.
-- Using local version for driver: '/srv/raid/filez/sandbox/AUR/falco/src/libs-10.2.0-driver'
-- Libs version: 0.0.0-local
-- Build type: release
-- Found uthash: include: /usr/include
-- Looking for strlcat
-- Looking for strlcat - found
-- Existing strlcpy found, will *not* use local definition
-- Existing strlcat found, will *not* use local definition
-- Found zlib: include: /usr/include, lib: /usr/lib/libz.so
-- Looking for sys/mkdev.h
-- Looking for sys/mkdev.h - not found
-- Looking for sys/sysmacros.h
-- Looking for sys/sysmacros.h - found
-- Build modern BPF engine
-- Found LIBELF: include: /usr/include, lib: /usr/lib/libelf.so
-- Found libbpf: include: /usr/include, lib: /usr/lib/libbpf.so
-- [MODERN BPF] MODERN_BPF_DEBUG_MODE: OFF
-- Driver API version 10.1.0
-- Driver schema version 4.5.1
-- [MODERN BPF] clang used by the modern bpf probe: '/usr/bin/clang'
-- [MODERN BPF] Found clang version: 22.1.8
-- [MODERN BPF] bpftool used by the modern bpf probe: '/usr/bin/bpftool'
-- [MODERN BPF] BPF system include flags: -idirafter /usr/lib/clang/22/include -idirafter /usr/local/include -idirafter /usr/include
-- [MODERN BPF] Target arch: x86
-- [MODERN BPF] Compilation flags: -g;-O2;-target;bpf;-D____;-D__TARGET_ARCH_x86;-D__USE_VMLINUX__;-I$<BUILD_INTERFACE:/usr/include>;-I/srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/driver/modern_bpf;-I/srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4;-isystem
-- [MODERN BPF] USE_BUNDLED_MODERN_BPF: Off, using skeleton dir: /srv/raid/filez/sandbox/AUR/falco/src/skeleton-build/skel_dir
-- [MODERN BPF] full skeleton path: /srv/raid/filez/sandbox/AUR/falco/src/skeleton-build/skel_dir/bpf_probe.skel.h
-- Found tbb: include: /usr/include/tbb, lib: /usr/lib/libtbb.so
-- Found jsoncpp: include: /usr/include, lib: /usr/lib/libjsoncpp.so
-- Found valijson: include: /usr/include.
-- Found re2: include: /usr/include, lib: /usr/lib/libre2.so
-- Using jsoncpp: include: /usr/include, lib: /usr/lib/libjsoncpp.so
-- Existing strlcpy found, will *not* use local definition
-- Existing strlcat found, will *not* use local definition
CMake Error at /srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap/CMakeLists.txt:64 (add_library):
add_library cannot create target "scap_error" because another target with
the same name already exists. The existing target is a static library
created in source directory
"/srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap". See
documentation for policy CMP0002 for more details.
CMake Error at /srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap/CMakeLists.txt:68 (add_library):
add_library cannot create target "scap" because another target with the
same name already exists. The existing target is a static library created
in source directory
"/srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap". See
documentation for policy CMP0002 for more details.
CMake Error at /srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap/CMakeLists.txt:79 (add_library):
add_library cannot create target "scap_platform_util" because another
target with the same name already exists. The existing target is a static
library created in source directory
"/srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap". See
documentation for policy CMP0002 for more details.
CMake Error at /srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap/CMakeLists.txt:91 (target_link_libraries):
Attempt to add link library "scap_error" to target "scap" which is not
built in this directory.
This is allowed only when policy CMP0079 is set to NEW.
CMake Error at /srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap/CMakeLists.txt:95 (add_library):
add_library cannot create target "scap_event_schema" because another target
with the same name already exists. The existing target is a static library
created in source directory
"/srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap". See
documentation for policy CMP0002 for more details.
CMake Error at /srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap/CMakeLists.txt:119 (target_link_libraries):
Attempt to add link library "scap_event_schema" to target "scap" which is
not built in this directory.
This is allowed only when policy CMP0079 is set to NEW.
CMake Error at /srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap/linux/CMakeLists.txt:15 (add_library):
add_library cannot create target "scap_platform" because another target
with the same name already exists. The existing target is a static library
created in source directory
"/srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap/linux".
See documentation for policy CMP0002 for more details.
CMake Error at /srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap/linux/CMakeLists.txt:27 (target_link_libraries):
Attempt to add link library "scap_error" to target "scap_platform" which is
not built in this directory.
This is allowed only when policy CMP0079 is set to NEW.
CMake Error at /srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap/CMakeLists.txt:126 (target_link_libraries):
Attempt to add link library "scap_platform" to target "scap" which is not
built in this directory.
This is allowed only when policy CMP0079 is set to NEW.
CMake Error at /srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap/CMakeLists.txt:128 (add_library):
add_library cannot create target "driver_event_schema" because another
target with the same name already exists. The existing target is a static
library created in source directory
"/srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap". See
documentation for policy CMP0002 for more details.
CMake Error at /srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap/CMakeLists.txt:130 (target_link_libraries):
Attempt to add link library "driver_event_schema" to target
"scap_event_schema" which is not built in this directory.
This is allowed only when policy CMP0079 is set to NEW.
CMake Error at /srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap/CMakeLists.txt:132 (add_library):
add_library cannot create target "scap_engine_util" because another target
with the same name already exists. The existing target is a static library
created in source directory
"/srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap". See
documentation for policy CMP0002 for more details.
CMake Error at /srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap/CMakeLists.txt:142 (target_link_libraries):
Attempt to add link library "scap_engine_util" to target "scap" which is
not built in this directory.
This is allowed only when policy CMP0079 is set to NEW.
CMake Error at /srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap/engine/noop/CMakeLists.txt:15 (add_library):
add_library cannot create target "scap_engine_noop" because another target
with the same name already exists. The existing target is a static library
created in source directory
"/srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap/engine/noop".
See documentation for policy CMP0002 for more details.
CMake Error at /srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap/engine/noop/CMakeLists.txt:25 (target_link_libraries):
Attempt to add link library "scap_error" to target "scap_engine_noop" which
is not built in this directory.
This is allowed only when policy CMP0079 is set to NEW.
CMake Error at /srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap/engine/nodriver/CMakeLists.txt:15 (add_library):
add_library cannot create target "scap_engine_nodriver" because another
target with the same name already exists. The existing target is a static
library created in source directory
"/srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap/engine/nodriver".
See documentation for policy CMP0002 for more details.
CMake Error at /srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap/engine/nodriver/CMakeLists.txt:16 (target_link_libraries):
Attempt to add link library "scap_engine_noop" to target
"scap_engine_nodriver" which is not built in this directory.
This is allowed only when policy CMP0079 is set to NEW.
CMake Error at /srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap/CMakeLists.txt:155 (target_link_libraries):
Attempt to add link library "scap_engine_nodriver" to target "scap" which
is not built in this directory.
This is allowed only when policy CMP0079 is set to NEW.
CMake Error at /srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap/engine/savefile/converter/CMakeLists.txt:18 (add_library):
add_library cannot create target "scap_savefile_converter" because another
target with the same name already exists. The existing target is created
in source directory
"/srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap/engine/savefile/converter".
See documentation for policy CMP0002 for more details.
CMake Error at /srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap/engine/savefile/converter/CMakeLists.txt:25 (target_link_libraries):
Attempt to add link library "scap_error" to target
"scap_savefile_converter" which is not built in this directory.
This is allowed only when policy CMP0079 is set to NEW.
CMake Error at /srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap/engine/savefile/CMakeLists.txt:18 (add_library):
add_library cannot create target "scap_engine_savefile" because another
target with the same name already exists. The existing target is a static
library created in source directory
"/srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap/engine/savefile".
See documentation for policy CMP0002 for more details.
CMake Error at /srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap/engine/savefile/CMakeLists.txt:21 (target_link_libraries):
Attempt to add link library "scap_engine_noop" to target
"scap_engine_savefile" which is not built in this directory.
This is allowed only when policy CMP0079 is set to NEW.
CMake Error at /srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap/CMakeLists.txt:166 (target_link_libraries):
Attempt to add link library "scap_engine_savefile" to target "scap" which
is not built in this directory.
This is allowed only when policy CMP0079 is set to NEW.
CMake Error at /srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap/engine/source_plugin/CMakeLists.txt:15 (add_library):
add_library cannot create target "scap_engine_source_plugin" because
another target with the same name already exists. The existing target is a
static library created in source directory
"/srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap/engine/source_plugin".
See documentation for policy CMP0002 for more details.
CMake Error at /srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap/engine/source_plugin/CMakeLists.txt:16 (target_link_libraries):
Attempt to add link library "scap_event_schema" to target
"scap_engine_source_plugin" which is not built in this directory.
This is allowed only when policy CMP0079 is set to NEW.
CMake Error at /srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap/CMakeLists.txt:171 (target_link_libraries):
Attempt to add link library "scap_engine_source_plugin" to target "scap"
which is not built in this directory.
This is allowed only when policy CMP0079 is set to NEW.
CMake Error at /srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap/engine/kmod/CMakeLists.txt:15 (add_library):
add_library cannot create target "scap_engine_kmod" because another target
with the same name already exists. The existing target is a static library
created in source directory
"/srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap/engine/kmod".
See documentation for policy CMP0002 for more details.
CMake Error at /srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap/engine/kmod/CMakeLists.txt:16 (target_link_libraries):
Attempt to add link library "scap_event_schema" to target
"scap_engine_kmod" which is not built in this directory.
This is allowed only when policy CMP0079 is set to NEW.
CMake Error at /srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap/CMakeLists.txt:176 (target_link_libraries):
Attempt to add link library "scap_engine_kmod" to target "scap" which is
not built in this directory.
This is allowed only when policy CMP0079 is set to NEW.
-- Build modern BPF engine
CMake Error at /srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap/engine/modern_bpf/CMakeLists.txt:35 (add_subdirectory):
The binary directory
/srv/raid/filez/sandbox/AUR/falco/src/skeleton-build/driver/modern_bpf
is already used to build a source directory. It cannot be used to build
source directory
/srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/driver/modern_bpf
Specify a unique binary directory name.
-- [MODERN BPF] USE_BUNDLED_MODERN_BPF: Off, using skeleton dir: /srv/raid/filez/sandbox/AUR/falco/src/skeleton-build/skel_dir
-- [MODERN BPF] full skeleton path: /srv/raid/filez/sandbox/AUR/falco/src/skeleton-build/skel_dir/bpf_probe.skel.h
CMake Error at /srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap/engine/modern_bpf/CMakeLists.txt:54 (add_subdirectory):
The binary directory
/srv/raid/filez/sandbox/AUR/falco/src/skeleton-build/libpman
is already used to build a source directory. It cannot be used to build
source directory
/srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libpman
Specify a unique binary directory name.
CMake Error at /srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap/engine/modern_bpf/CMakeLists.txt:56 (add_library):
add_library cannot create target "scap_engine_modern_bpf" because another
target with the same name already exists. The existing target is a static
library created in source directory
"/srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap/engine/modern_bpf".
See documentation for policy CMP0002 for more details.
CMake Error at /srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap/engine/modern_bpf/CMakeLists.txt:58 (target_link_libraries):
Attempt to add link library "pman" to target "scap_engine_modern_bpf" which
is not built in this directory.
This is allowed only when policy CMP0079 is set to NEW.
CMake Error at /srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libscap/CMakeLists.txt:182 (target_link_libraries):
Attempt to add link library "scap_engine_modern_bpf" to target "scap" which
is not built in this directory.
This is allowed only when policy CMP0079 is set to NEW.
-- Using jsoncpp: include: /usr/include, lib: /usr/lib/libjsoncpp.so
-- Using re2: include: /usr/include, lib: /usr/lib/libre2.so
CMake Error at /srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/cmake/modules/libsinsp.cmake:60 (add_subdirectory):
The binary directory
/srv/raid/filez/sandbox/AUR/falco/src/skeleton-build/libsinsp
is already used to build a source directory. It cannot be used to build
source directory
/srv/raid/filez/sandbox/AUR/falco/src/libs-0.25.4/userspace/libsinsp
Specify a unique binary directory name.
Call Stack (most recent call first):
cmake/modules/falcosecurity-libs.cmake:177 (include)
CMakeLists.txt:162 (include)
-- Falco version: 0.44.1
-- Will use mem allocator library:
-- Found nlohmann_json: /usr/share/cmake/nlohmann_json/nlohmann_jsonConfig.cmake (found version "3.12.0")
-- Found CURL: /usr/lib/libcurl.so (found version "8.21.0")
-- Found CURL: include: /usr/include, lib: /usr/lib/libcurl.so
-- Found OpenSSL: /usr/lib/libcrypto.so (found version "3.6.3")
-- Found OpenSSL: include: /usr/include, lib: /usr/lib/libssl.so;/usr/lib/libcrypto.so
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD - Success
-- Found Threads: TRUE
-- Found OpenSSL: /usr/lib/libcrypto.so (found suitable version "3.6.3", minimum required is "3.0.0") found components: Crypto SSL
-- Found ZLIB: /usr/lib/libz.so (found version "1.3.2")
-- Found Brotli: /usr/include found components: common encoder decoder
-- Found httplib: /usr/include/httplib.h (found version "0.48.0")
-- cppcheck found at: /usr/bin/cppcheck
-- cppcheck-htmlreport found at: /usr/bin/cppcheck-htmlreport
-- Building with falcoctl: 0.13.0
-- Fetching container plugin 0.7.1 in '/srv/raid/filez/sandbox/AUR/falco/src/skeleton-build/container_plugin-prefix/src/container_plugin/libcontainer.so'
-- Using package generators: DEB;RPM;TGZ
-- Package architecture: x86_64
-- Configuring incomplete, errors occurred!Environment
cmakeversion 4.4.2Linux example.com 7.0.10-arch1-1 #1 SMP PREEMPT_DYNAMIC Tue, 26 May 2026 08:58:32 +0000 x86_64 GNU/Linux
Additional context
Also, knob -DUSE_BUNDLED_DEPS=Off should use system libs, but it's not until -DUSE_BUNDLED_{RE2,OPENSSL,ETC} is not set off manually. Each...
Source: falcosecurity/falco