drivers: add reasons for components being disabled

For each driver where we optionally disable it, add in the reason why it's
being disabled, so the user knows how to fix it.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Acked-by: Luca Boccassi <bluca@debian.org>

52 files changed, 73 insertions, 20 deletions

diff --git a/drivers/bus/dpaa/meson.build b/drivers/bus/dpaa/meson.build
index 1c8ca8c..19daaa5 100644
--- a/drivers/bus/dpaa/meson.build
+++ b/drivers/bus/dpaa/meson.build
@@ -4,7 +4,8 @@
 version = 2
 
 if not is_linux
-        build = false
+	build = false
+	reason = 'only supported on linux'
 endif
 
 deps += ['common_dpaax', 'eventdev']
diff --git a/drivers/bus/fslmc/meson.build b/drivers/bus/fslmc/meson.build
index 04624c3..faebc43 100644
--- a/drivers/bus/fslmc/meson.build
+++ b/drivers/bus/fslmc/meson.build
@@ -4,7 +4,8 @@
 version = 2
 
 if not is_linux
-        build = false
+	build = false
+	reason = 'only supported on linux'
 endif
 
 deps += ['common_dpaax', 'eventdev', 'kvargs']
diff --git a/drivers/bus/vmbus/meson.build b/drivers/bus/vmbus/meson.build
index 9fd430d..79d4c68 100644
--- a/drivers/bus/vmbus/meson.build
+++ b/drivers/bus/vmbus/meson.build
@@ -17,4 +17,5 @@ if is_linux
 	includes += include_directories('linux')
 else
 	build = false
+	reason = 'only supported on linux'
 endif
diff --git a/drivers/common/dpaax/meson.build b/drivers/common/dpaax/meson.build
index 78378e2..a315e77 100644
--- a/drivers/common/dpaax/meson.build
+++ b/drivers/common/dpaax/meson.build
@@ -4,7 +4,8 @@
 allow_experimental_apis = true
 
 if not is_linux
-        build = false
+	build = false
+	reason = 'only supported on linux'
 endif
 
 sources = files('dpaax_iova_table.c')
diff --git a/drivers/common/mvep/meson.build b/drivers/common/mvep/meson.build
index 8ccfacb..8df4bc6 100644
--- a/drivers/common/mvep/meson.build
+++ b/drivers/common/mvep/meson.build
@@ -10,6 +10,7 @@ inc_dir = path + '/include'
 lib = cc.find_library('libmusdk', dirs: [lib_dir], required: false)
 if not lib.found()
 	build = false
+	reason = 'missing dependency, "libmusdk"'
 else
 	ext_deps += lib
 	includes += include_directories(inc_dir)
diff --git a/drivers/common/qat/meson.build b/drivers/common/qat/meson.build
index 80b6b25..8de2492 100644
--- a/drivers/common/qat/meson.build
+++ b/drivers/common/qat/meson.build
@@ -4,6 +4,7 @@
 # This does not build a driver, but instead holds common files for
 # the crypto and compression drivers.
 build = false
+reason = '' # sentinal value to suppress printout
 qat_deps = ['bus_pci']
 qat_sources = files('qat_common.c',
 		'qat_qp.c',
diff --git a/drivers/compress/isal/meson.build b/drivers/compress/isal/meson.build
index 94c10fd..67b5c4a 100644
--- a/drivers/compress/isal/meson.build
+++ b/drivers/compress/isal/meson.build
@@ -3,7 +3,8 @@
 
 dep = dependency('libisal', required: false)
 if not dep.found()
-       build =false
+	build = false
+	reason = 'missing dependency, "libisal"'
 endif
 
 deps += 'bus_vdev'
diff --git a/drivers/compress/zlib/meson.build b/drivers/compress/zlib/meson.build
index b036703..b1328c5 100644
--- a/drivers/compress/zlib/meson.build
+++ b/drivers/compress/zlib/meson.build
@@ -4,6 +4,7 @@
 dep = dependency('zlib', required: false)
 if not dep.found()
 	build = false
+	reason = 'missing dependency, "zlib"'
 endif
 
 deps += 'bus_vdev'
diff --git a/drivers/crypto/aesni_gcm/meson.build b/drivers/crypto/aesni_gcm/meson.build
index 7183cfc..3a6e332 100644
--- a/drivers/crypto/aesni_gcm/meson.build
+++ b/drivers/crypto/aesni_gcm/meson.build
@@ -5,6 +5,7 @@ IMB_required_ver = '0.52.0'
 lib = cc.find_library('IPSec_MB', required: false)
 if not lib.found()
 	build = false
+	reason = 'missing dependency, "libIPSec_MB"'
 else
 	ext_deps += lib
 
@@ -13,8 +14,8 @@ else
 		prefix : '#include<intel-ipsec-mb.h>').split('"')[1]
 
 	if (imb_ver == '') or (imb_ver.version_compare('<' + IMB_required_ver))
-		message('IPSec_MB version >= @0@ is required, found version @1@'.format(
-				IMB_required_ver, imb_ver))
+		reason = 'IPSec_MB version >= @0@ is required, found version @1@'.format(
+				IMB_required_ver, imb_ver)
 		build = false
 	endif
 endif
diff --git a/drivers/crypto/aesni_mb/meson.build b/drivers/crypto/aesni_mb/meson.build
index 7c1eb3f..3e16874 100644
--- a/drivers/crypto/aesni_mb/meson.build
+++ b/drivers/crypto/aesni_mb/meson.build
@@ -5,6 +5,7 @@ IMB_required_ver = '0.52.0'
 lib = cc.find_library('IPSec_MB', required: false)
 if not lib.found()
 	build = false
+	reason = 'missing dependency, "libIPSec_MB"'
 else
 	ext_deps += lib
 
@@ -13,8 +14,8 @@ else
 		prefix : '#include<intel-ipsec-mb.h>').split('"')[1]
 
 	if (imb_ver == '') or (imb_ver.version_compare('<' + IMB_required_ver))
-		message('IPSec_MB version >= @0@ is required, found version @1@'.format(
-				IMB_required_ver, imb_ver))
+		reason = 'IPSec_MB version >= @0@ is required, found version @1@'.format(
+				IMB_required_ver, imb_ver)
 		build = false
 	endif
 
diff --git a/drivers/crypto/caam_jr/meson.build b/drivers/crypto/caam_jr/meson.build
index e61a13c..4c66dd8 100644
--- a/drivers/crypto/caam_jr/meson.build
+++ b/drivers/crypto/caam_jr/meson.build
@@ -2,7 +2,8 @@
 # Copyright 2018 NXP
 
 if not is_linux
-        build = false
+	build = false
+	reason = 'only supported on linux'
 endif
 
 deps += ['bus_vdev', 'bus_dpaa', 'security']
diff --git a/drivers/crypto/ccp/meson.build b/drivers/crypto/ccp/meson.build
index 071ccc5..6f7217a 100644
--- a/drivers/crypto/ccp/meson.build
+++ b/drivers/crypto/ccp/meson.build
@@ -2,11 +2,13 @@
 # Copyright(c) 2018 Advanced Micro Devices, Inc. All rights reserved.
 
 if not is_linux
-        build = false
+	build = false
+	reason = 'only supported on linux'
 endif
 dep = dependency('libcrypto', required: false)
 if not dep.found()
 	build = false
+	reason = 'missing dependency, "libcrypto"'
 endif
 deps += 'bus_vdev'
 deps += 'bus_pci'
diff --git a/drivers/crypto/dpaa2_sec/meson.build b/drivers/crypto/dpaa2_sec/meson.build
index d197cda..23affa8 100644
--- a/drivers/crypto/dpaa2_sec/meson.build
+++ b/drivers/crypto/dpaa2_sec/meson.build
@@ -4,7 +4,8 @@
 version = 2
 
 if not is_linux
-        build = false
+	build = false
+	reason = 'only supported on linux'
 endif
 
 deps += ['security', 'mempool_dpaa2']
diff --git a/drivers/crypto/dpaa_sec/meson.build b/drivers/crypto/dpaa_sec/meson.build
index 134af88..7b9a019 100644
--- a/drivers/crypto/dpaa_sec/meson.build
+++ b/drivers/crypto/dpaa_sec/meson.build
@@ -2,7 +2,8 @@
 # Copyright 2018 NXP
 
 if not is_linux
-        build = false
+	build = false
+	reason = 'only supported on linux'
 endif
 
 deps += ['bus_dpaa', 'security']
diff --git a/drivers/crypto/kasumi/meson.build b/drivers/crypto/kasumi/meson.build
index 0fa3017..90a3c4f 100644
--- a/drivers/crypto/kasumi/meson.build
+++ b/drivers/crypto/kasumi/meson.build
@@ -4,6 +4,7 @@
 lib = cc.find_library('sso_kasumi', required: false)
 if not lib.found() or not cc.has_header('sso_kasumi.h')
 	build = false
+	reason = 'missing dependency, "libsso_kasumi"'
 	subdir_done()
 endif
 
diff --git a/drivers/crypto/mvsam/meson.build b/drivers/crypto/mvsam/meson.build
index f1c8796..6d97dc8 100644
--- a/drivers/crypto/mvsam/meson.build
+++ b/drivers/crypto/mvsam/meson.build
@@ -10,6 +10,7 @@ inc_dir = path + '/include'
 lib = cc.find_library('libmusdk', dirs: [lib_dir], required: false)
 if not lib.found()
 	build = false
+	reason = 'missing dependency, "libmusdk"'
 else
 	ext_deps += lib
 	includes += include_directories(inc_dir)
diff --git a/drivers/crypto/octeontx/meson.build b/drivers/crypto/octeontx/meson.build
index a9f2d31..63a59c5 100644
--- a/drivers/crypto/octeontx/meson.build
+++ b/drivers/crypto/octeontx/meson.build
@@ -2,6 +2,7 @@
 # Copyright(c) 2018 Cavium, Inc
 if not is_linux
 	build = false
+	reason = 'only supported on linux'
 endif
 
 deps += ['bus_pci']
diff --git a/drivers/crypto/openssl/meson.build b/drivers/crypto/openssl/meson.build
index d56a323..394e74c 100644
--- a/drivers/crypto/openssl/meson.build
+++ b/drivers/crypto/openssl/meson.build
@@ -4,6 +4,7 @@
 dep = dependency('libcrypto', required: false)
 if not dep.found()
 	build = false
+	reason = 'missing dependency, "libcrypto"'
 endif
 allow_experimental_apis = true
 deps += 'bus_vdev'
diff --git a/drivers/crypto/qat/meson.build b/drivers/crypto/qat/meson.build
index 710b081..fc65923 100644
--- a/drivers/crypto/qat/meson.build
+++ b/drivers/crypto/qat/meson.build
@@ -4,6 +4,7 @@
 # this does not build the QAT driver, instead that is done in the compression
 # driver which comes later. Here we just add our sources files to the list
 build = false
+reason = '' # sentinal value to suppress printout
 dep = dependency('libcrypto', required: false)
 qat_includes += include_directories('.')
 qat_deps += 'cryptodev'
diff --git a/drivers/crypto/snow3g/meson.build b/drivers/crypto/snow3g/meson.build
index c566a5f..0e8742a 100644
--- a/drivers/crypto/snow3g/meson.build
+++ b/drivers/crypto/snow3g/meson.build
@@ -4,6 +4,7 @@
 lib = cc.find_library('sso_snow3g', required: false)
 if not lib.found() or not cc.has_header('sso_snow3g.h')
 	build = false
+	reason = 'missing dependency, "libsso_snow3g"'
 	subdir_done()
 endif
 
diff --git a/drivers/crypto/zuc/meson.build b/drivers/crypto/zuc/meson.build
index fc29002..b231de0 100644
--- a/drivers/crypto/zuc/meson.build
+++ b/drivers/crypto/zuc/meson.build
@@ -4,6 +4,7 @@
 lib = cc.find_library('sso_zuc', required: false)
 if not lib.found() or not cc.has_header('sso_zuc.h')
 	build = false
+	reason = 'missing dependency, "libsso_zuc"'
 	subdir_done()
 endif
 
diff --git a/drivers/event/dpaa/meson.build b/drivers/event/dpaa/meson.build
index 11b1fe6..c1e7254 100644
--- a/drivers/event/dpaa/meson.build
+++ b/drivers/event/dpaa/meson.build
@@ -3,6 +3,7 @@
 
 if not is_linux
 	build = false
+	reason = 'only supported on linux'
 endif
 deps += ['pmd_dpaa']
 sources = files('dpaa_eventdev.c')
diff --git a/drivers/event/dpaa2/meson.build b/drivers/event/dpaa2/meson.build
index a94bc56..f7da7fa 100644
--- a/drivers/event/dpaa2/meson.build
+++ b/drivers/event/dpaa2/meson.build
@@ -5,6 +5,7 @@ version = 2
 
 if not is_linux
 	build = false
+	reason = 'only supported on linux'
 endif
 deps += ['bus_vdev', 'pmd_dpaa2', 'pmd_dpaa2_sec']
 sources = files('dpaa2_hw_dpcon.c',
diff --git a/drivers/mempool/dpaa/meson.build b/drivers/mempool/dpaa/meson.build
index c4c8ebc..b7446f1 100644
--- a/drivers/mempool/dpaa/meson.build
+++ b/drivers/mempool/dpaa/meson.build
@@ -2,7 +2,8 @@
 # Copyright 2018 NXP
 
 if not is_linux
-        build = false
+	build = false
+	reason = 'only supported on linux'
 endif
 
 deps += ['bus_dpaa']
diff --git a/drivers/mempool/dpaa2/meson.build b/drivers/mempool/dpaa2/meson.build
index 9a8b28d..3d25ba0 100644
--- a/drivers/mempool/dpaa2/meson.build
+++ b/drivers/mempool/dpaa2/meson.build
@@ -4,7 +4,8 @@
 version = 2
 
 if not is_linux
-        build = false
+	build = false
+	reason = 'only supported on linux'
 endif
 
 deps += ['bus_fslmc']
diff --git a/drivers/net/af_packet/meson.build b/drivers/net/af_packet/meson.build
index 92c306c..a7f392e 100644
--- a/drivers/net/af_packet/meson.build
+++ b/drivers/net/af_packet/meson.build
@@ -3,5 +3,6 @@
 
 if not is_linux
 	build = false
+	reason = 'only supported on linux'
 endif
 sources = files('rte_eth_af_packet.c')
diff --git a/drivers/net/af_xdp/meson.build b/drivers/net/af_xdp/meson.build
index 7904840..ac679b9 100644
--- a/drivers/net/af_xdp/meson.build
+++ b/drivers/net/af_xdp/meson.build
@@ -13,4 +13,5 @@ if bpf_dep.found() and cc.has_header('bpf/xsk.h') and cc.has_header('linux/if_xd
 	pkgconfig_extra_libs += '-lbpf'
 else
 	build = false
+	reason = 'missing dependency, "libbpf"'
 endif
diff --git a/drivers/net/avp/meson.build b/drivers/net/avp/meson.build
index 8138cb2..a5f63cd 100644
--- a/drivers/net/avp/meson.build
+++ b/drivers/net/avp/meson.build
@@ -2,7 +2,8 @@
 # Copyright(c) 2018 Intel Corporation
 
 if not is_linux
-        build = false
+	build = false
+	reason = 'only supported on linux'
 endif
 sources = files('avp_ethdev.c')
 install_headers('rte_avp_common.h', 'rte_avp_fifo.h')
diff --git a/drivers/net/axgbe/meson.build b/drivers/net/axgbe/meson.build
index 6decb25..86873b7 100644
--- a/drivers/net/axgbe/meson.build
+++ b/drivers/net/axgbe/meson.build
@@ -3,6 +3,7 @@
 
 if not is_linux
 	build = false
+	reason = 'only supported on linux'
 endif
 
 sources = files('axgbe_ethdev.c',
diff --git a/drivers/net/bnx2x/meson.build b/drivers/net/bnx2x/meson.build
index dd189ff..4892bb2 100644
--- a/drivers/net/bnx2x/meson.build
+++ b/drivers/net/bnx2x/meson.build
@@ -3,6 +3,7 @@
 
 dep = dependency('zlib', required: false)
 build = dep.found()
+reason = 'missing dependency, "zlib"'
 ext_deps += dep
 cflags += '-DZLIB_CONST'
 sources = files('bnx2x.c',
diff --git a/drivers/net/dpaa/meson.build b/drivers/net/dpaa/meson.build
index 8e5418b..94c0e22 100644
--- a/drivers/net/dpaa/meson.build
+++ b/drivers/net/dpaa/meson.build
@@ -3,6 +3,7 @@
 
 if not is_linux
 	build = false
+	reason = 'only supported on linux'
 endif
 deps += ['mempool_dpaa']
 
diff --git a/drivers/net/dpaa2/meson.build b/drivers/net/dpaa2/meson.build
index a0ea992..7e74c65 100644
--- a/drivers/net/dpaa2/meson.build
+++ b/drivers/net/dpaa2/meson.build
@@ -4,7 +4,8 @@
 version = 2
 
 if not is_linux
-        build = false
+	build = false
+	reason = 'only supported on linux'
 endif
 
 deps += ['mempool_dpaa2']
diff --git a/drivers/net/enetc/meson.build b/drivers/net/enetc/meson.build
index 7d0c2ff..3bc0698 100644
--- a/drivers/net/enetc/meson.build
+++ b/drivers/net/enetc/meson.build
@@ -3,6 +3,7 @@
 
 if not is_linux
 	build = false
+	reason = 'only supported on linux'
 endif
 
 sources = files('enetc_ethdev.c',
diff --git a/drivers/net/ifc/meson.build b/drivers/net/ifc/meson.build
index 72df070..adc9ed9 100644
--- a/drivers/net/ifc/meson.build
+++ b/drivers/net/ifc/meson.build
@@ -2,6 +2,7 @@
 # Copyright(c) 2018 Intel Corporation
 
 build = dpdk_conf.has('RTE_LIBRTE_VHOST')
+reason = 'missing dependency, DPDK vhost library'
 allow_experimental_apis = true
 sources = files('ifcvf_vdpa.c', 'base/ifcvf.c')
 includes += include_directories('base')
diff --git a/drivers/net/kni/meson.build b/drivers/net/kni/meson.build
index e3b2d83..0539b47 100644
--- a/drivers/net/kni/meson.build
+++ b/drivers/net/kni/meson.build
@@ -3,5 +3,6 @@
 
 # this driver can be built if-and-only-if KNI library is buildable
 build = dpdk_conf.has('RTE_LIBRTE_KNI')
+reason = 'missing dependency, DPDK KNI library'
 sources = files('rte_eth_kni.c')
 deps += 'kni'
diff --git a/drivers/net/mlx4/meson.build b/drivers/net/mlx4/meson.build
index 2540489..5de04b7 100644
--- a/drivers/net/mlx4/meson.build
+++ b/drivers/net/mlx4/meson.build
@@ -25,6 +25,7 @@ foreach libname:libnames
 		libs += [ lib ]
 	else
 		build = false
+		reason = 'missing dependency, "' + libname + '"'
 	endif
 endforeach
 # Compile PMD
diff --git a/drivers/net/mlx5/meson.build b/drivers/net/mlx5/meson.build
index ac3b529..22ddd54 100644
--- a/drivers/net/mlx5/meson.build
+++ b/drivers/net/mlx5/meson.build
@@ -25,6 +25,7 @@ foreach libname:libnames
 		libs += [ lib ]
 	else
 		build = false
+		reason = 'missing dependency, "' + libname + '"'
 	endif
 endforeach
 if build
diff --git a/drivers/net/mvneta/meson.build b/drivers/net/mvneta/meson.build
index c0b1bce..8d72027 100644
--- a/drivers/net/mvneta/meson.build
+++ b/drivers/net/mvneta/meson.build
@@ -10,6 +10,7 @@ inc_dir = path + '/include'
 lib = cc.find_library('libmusdk', dirs : [lib_dir], required: false)
 if not lib.found()
 	build = false
+	reason = 'missing dependency, "libmusdk"'
 else
 	ext_deps += lib
 	includes += include_directories(inc_dir)
diff --git a/drivers/net/mvpp2/meson.build b/drivers/net/mvpp2/meson.build
index 70ef2d6..e06edda 100644
--- a/drivers/net/mvpp2/meson.build
+++ b/drivers/net/mvpp2/meson.build
@@ -10,6 +10,7 @@ inc_dir = path + '/include'
 lib = cc.find_library('libmusdk', dirs : [lib_dir], required: false)
 if not lib.found()
 	build = false
+	reason = 'missing dependency, "libmusdk"'
 else
 	ext_deps += lib
 	includes += include_directories(inc_dir)
diff --git a/drivers/net/netvsc/meson.build b/drivers/net/netvsc/meson.build
index c842697..e9fe353 100644
--- a/drivers/net/netvsc/meson.build
+++ b/drivers/net/netvsc/meson.build
@@ -2,6 +2,7 @@
 # Copyright(c) 2018 Microsoft Corporation
 
 build = dpdk_conf.has('RTE_LIBRTE_VMBUS_BUS')
+reason = 'missing dependency, DPDK VMBus driver'
 version = 2
 sources = files('hn_ethdev.c', 'hn_rxtx.c', 'hn_rndis.c', 'hn_nvs.c', 'hn_vf.c')
 
diff --git a/drivers/net/nfb/meson.build b/drivers/net/nfb/meson.build
index 457955d..4502c3f 100644
--- a/drivers/net/nfb/meson.build
+++ b/drivers/net/nfb/meson.build
@@ -4,6 +4,7 @@
 # All rights reserved.
 
 dep = cc.find_library('nfb', required: false)
+reason = 'missing dependency, "libnfb"'
 
 build = dep.found() and cc.has_header('nfb/nfb.h', dependencies: dep)
 
diff --git a/drivers/net/nfp/meson.build b/drivers/net/nfp/meson.build
index 8c87c5b..b487cdf 100644
--- a/drivers/net/nfp/meson.build
+++ b/drivers/net/nfp/meson.build
@@ -2,7 +2,8 @@
 # Copyright(c) 2018 Intel Corporation
 
 if not is_linux or not dpdk_conf.get('RTE_ARCH_64')
-        build = false
+	build = false
+	reason = 'only supported on 64-bit linux'
 endif
 sources = files('nfpcore/nfp_cpp_pcie_ops.c',
 	'nfpcore/nfp_nsp.c',
diff --git a/drivers/net/pcap/meson.build b/drivers/net/pcap/meson.build
index 2c2fd11..910dfab 100644
--- a/drivers/net/pcap/meson.build
+++ b/drivers/net/pcap/meson.build
@@ -14,6 +14,7 @@ else
 		pkgconfig_extra_libs += '-lpcap'
 	else
 		build = false
+		reason = 'missing dependency, "libpcap"'
 	endif
 endif
 sources = files('rte_eth_pcap.c')
diff --git a/drivers/net/sfc/meson.build b/drivers/net/sfc/meson.build
index e675609..4fb0d0a 100644
--- a/drivers/net/sfc/meson.build
+++ b/drivers/net/sfc/meson.build
@@ -8,6 +8,7 @@
 
 if arch_subdir != 'x86' or not dpdk_conf.get('RTE_ARCH_64')
 	build = false
+	reason = 'only supported on x86_64'
 endif
 
 allow_experimental_apis = true
diff --git a/drivers/net/softnic/meson.build b/drivers/net/softnic/meson.build
index dd1d610..9c10c2e 100644
--- a/drivers/net/softnic/meson.build
+++ b/drivers/net/softnic/meson.build
@@ -2,7 +2,8 @@
 # Copyright(c) 2018 Intel Corporation
 
 if not is_linux
-        build = false
+	build = false
+	reason = 'only supported on linux'
 endif
 allow_experimental_apis = true
 install_headers('rte_eth_softnic.h')
diff --git a/drivers/net/szedata2/meson.build b/drivers/net/szedata2/meson.build
index da37337..032b425 100644
--- a/drivers/net/szedata2/meson.build
+++ b/drivers/net/szedata2/meson.build
@@ -3,5 +3,6 @@
 
 dep = cc.find_library('sze2', required: false)
 build = dep.found()
+reason = 'missing dependency, "libsze2"'
 ext_deps += dep
 sources = files('rte_eth_szedata2.c')
diff --git a/drivers/net/tap/meson.build b/drivers/net/tap/meson.build
index c407a1f..baa70f7 100644
--- a/drivers/net/tap/meson.build
+++ b/drivers/net/tap/meson.build
@@ -2,7 +2,8 @@
 # Copyright 2018 Luca Boccassi <bluca@debian.org>
 
 if not is_linux
-        build = false
+	build = false
+	reason = 'only supported on linux'
 endif
 sources = files(
 	'rte_eth_tap.c',
diff --git a/drivers/net/vdev_netvsc/meson.build b/drivers/net/vdev_netvsc/meson.build
index 6655859..c82c547 100644
--- a/drivers/net/vdev_netvsc/meson.build
+++ b/drivers/net/vdev_netvsc/meson.build
@@ -2,7 +2,8 @@
 # Copyright(c) 2018 Luca Boccassi <bluca@debian.org>
 
 if not is_linux
-        build = false
+	build = false
+	reason = 'only supported on linux'
 endif
 sources = files('vdev_netvsc.c')
 
diff --git a/drivers/net/vhost/meson.build b/drivers/net/vhost/meson.build
index 9b067c3..9532a76 100644
--- a/drivers/net/vhost/meson.build
+++ b/drivers/net/vhost/meson.build
@@ -2,6 +2,7 @@
 # Copyright(c) 2018 Intel Corporation
 
 build = dpdk_conf.has('RTE_LIBRTE_VHOST')
+reason = 'missing dependency, DPDK vhost library'
 version = 2
 sources = files('rte_eth_vhost.c')
 install_headers('rte_eth_vhost.h')
diff --git a/drivers/raw/dpaa2_cmdif/meson.build b/drivers/raw/dpaa2_cmdif/meson.build
index 37bb24a..9ba1ae2 100644
--- a/drivers/raw/dpaa2_cmdif/meson.build
+++ b/drivers/raw/dpaa2_cmdif/meson.build
@@ -4,6 +4,7 @@
 version = 2
 
 build = dpdk_conf.has('RTE_LIBRTE_DPAA2_MEMPOOL')
+reason = 'missing dependency, DPDK DPAA2 mempool driver'
 deps += ['rawdev', 'mempool_dpaa2', 'bus_vdev']
 sources = files('dpaa2_cmdif.c')
 
diff --git a/drivers/raw/dpaa2_qdma/meson.build b/drivers/raw/dpaa2_qdma/meson.build
index 1577946..f70ade3 100644
--- a/drivers/raw/dpaa2_qdma/meson.build
+++ b/drivers/raw/dpaa2_qdma/meson.build
@@ -4,6 +4,7 @@
 version = 2
 
 build = dpdk_conf.has('RTE_LIBRTE_DPAA2_MEMPOOL')
+reason = 'missing dependency, DPDK DPAA2 mempool driver'
 deps += ['rawdev', 'mempool_dpaa2', 'ring', 'kvargs']
 sources = files('dpaa2_qdma.c')
 
diff --git a/drivers/raw/ifpga_rawdev/meson.build b/drivers/raw/ifpga_rawdev/meson.build
index 132b777..0ab6fd7 100644
--- a/drivers/raw/ifpga_rawdev/meson.build
+++ b/drivers/raw/ifpga_rawdev/meson.build
@@ -9,6 +9,7 @@ objs = [base_objs]
 dep = dependency('libfdt', required: false)
 if not dep.found()
 	build = false
+	reason = 'missing dependency, "libfdt"'
 endif
 deps += ['rawdev', 'pci', 'bus_pci', 'kvargs',
 	'bus_vdev', 'bus_ifpga', 'net']