[Python] Not all files have gcno with bazel --coverage

NB I have the custom targets which run by python scripts. So I couldn't use bazel coverage directly for this one.

1.

• I defined in .bazelrc

build:coverage --collect_code_coverage
build:coverage --instrumentation_filter="^//src[/:]"
coverage --instrumentation_filter="^//src[/:]"

• In the root BUILD

config_setting(
name = "Coverage",
flag_values = {
":coverage": "true",
},
)

bool_flag(
name = "coverage",
build_setting_default = False,
)

• In the cc_binary wrapper I use

+ select({"//:Coverage": coverageCopts, "//conditions:default": [], }),
// and
select({"//:Coverage": coverageLopts, "//conditions:default": [], }),


where

coverageCopts = ["--coverage", "-fprofile-abs-path", "-fprofile-arcs", "-ftest-coverage"]
coverageLopts = ["--coverage", "-lgcov"]

• and run this python script (from bazel) like this:

bazel run --subcommands --//\:coverage=true script:runner

1. 
   But for some mystical reasons I have a lack of gcno files.
   
   
2. 
   although there are these gcno's for neighboring files from the same library.
   
   
3. 
   Grepping for bazel --subcommands indicates the presences of --coverage flag for this cpp file.
   
   
4. 
   I did bazel clean --expunge - same result.
   

Continue reading...