Running in Travis CI, weird behavior of $(shell) in a Makefile?

Deployment
1

I’m experiencing behavior where a gmake $(shell) construct that works in my local environment fails under certain conditions when running within Travis CI invoked from github. When invoking the gmake construct

$(shell echo ‘{gen}’ | sed -e “s#{gen}#$(GEN)#”)

as part of a make action, it works fine both in my local Debian environment and inside CI. But when invoking it to set a Makefile variable:

SPECSRC = $(shell echo ‘{gen}’ | sed -e “s#{gen}#$(GEN)#”)

it still works locally, but fails when [executed under Travis:

mf.test:11: *** unterminated call to function ‘shell’: missing ‘)’. Stop.

I’ve checked some obvious things - both are running /bin/bash in their respective environments, and there are very close (not identical) gmake / sed / bash versions in the two environments. Alternate sed-expression separators like ‘@’ instead of ‘#’ (see mf.test below) do not help.

2

The issue arises from differing versions of GNU Make on Travis. Your makefile syntax isn’t universally compatible across GNU Make versions, specifically due to the handling of the comment character # in variable/function references in some older GNU Make versions.

To ensure portability in your makefile, encapsulate the comment character # within a variable like so:

HASH := \#
SPECSRC := $(shell echo '{gen}' | sed -e "s$(HASH){gen}$(HASH)$(GEN)$(HASH)")

Additionally, it’s generally inadvisable to use recursive assignment = with $(shell ...). In most cases, you should opt for simple assignment := instead. This recommendation, however, is not directly related to the issue you’re facing.

3

So to add additional files into the RPM package, I have added a custom install_script in the RPM spec file. This script copies files from the build directory into RPM_BUILD_ROOT. For example:

%install
make install DESTDIR=$RPM_BUILD_ROOT
%install_script
cp %{buildroot}/path/to/file1 $RPM_BUILD_ROOT/
cp {buildroot}/path/to/file2 $RPM_BUILD_ROOT/

Alternatively, I could have ran ‘make install’ directly in the %install section, or use the %make_install macro. Still no luck.

4

You could use xargs with I and a place-holder {} to store the value stdin and pass it over to sed as:

date +%s | md5sum | cut -d' ' -f 1 | xargs -I {} sed -i.bak 's/^\(CSS=\).*/CSS={}/' file

Although I would wisely avoid introducing another pipe-line and would use a separated command for sed:

newHash=$(date +%s | md5sum | cut -d' ' -f 1); sed -i.bak "s/^\(CSS=\).*/CSS=${newHash}/" file
1 Like
5

used your workaround (the example using sed, and args) it’s kind of a weird one but it worked. thanks @montana

6

Great to hear I was able to solve your issue.