CAMERA: Conda dependency seemingly installed but failed to build job environment

Fix :v:

For records
$ /shared/mfs/data/galaxy/mutable-data/dependencies/_conda/bin/conda create --quiet --override-channels --channel iuc --channel conda-forge --channel bioconda --channel defaults --name mulled-v1-bc992e514690c52fa4dc473ae4933b4a990f1f279f269d1f17fa2031c5225d95 r-snow bioconductor-camera=1.26.0 bioconductor-multtest r-batch graphicsmagick bioconductor-biobase==2.34.0
$ source /shared/mfs/data/galaxy/mutable-data/dependencies/_conda/bin/activate /shared/mfs/data/galaxy/mutable-data/dependencies/_conda/envs/mulled-v1-bc992e514690c52fa4dc473ae4933b4a990f1f279f269d1f17fa2031c5225d95
$ conda install --override-channels --channel iuc --channel conda-forge --channel bioconda --channel defaults --channel https://repo.anaconda.com/pkgs/free libnetcdf=4.3.3.1
$ conda install -y --override-channels --channel iuc --channel conda-forge --channel bioconda --channel defaults --channel https://repo.anaconda.com/pkgs/free bioconductor-mzr=2.6.3=r3.4.1_1
$ conda list
# Name                    Version                   Build  Channel
_libgcc_mutex             0.1                 conda_forge    conda-forge
_openmp_mutex             4.5                       1_gnu    conda-forge
_r-mutex                  1.0.1               anacondar_1    conda-forge
bioconductor-biobase      2.34.0                 r3.4.1_0    bioconda
bioconductor-biocgenerics 0.26.0                   r341_0    bioconda
bioconductor-biocparallel 1.14.2           r341h26a2512_0    bioconda
bioconductor-camera       1.26.0                        0    bioconda
bioconductor-graph        1.58.2           r341h470a237_0    bioconda
bioconductor-massspecwavelet 1.46.0           r341h470a237_0    bioconda
bioconductor-multtest     2.34.0                 r3.4.1_0    bioconda
bioconductor-mzr          2.6.3                  r3.4.1_1    bioconda
bioconductor-protgenerics 1.12.0                   r341_0    bioconda
bioconductor-rbgl         1.56.0           r341hfc679d8_0    bioconda
bioconductor-s4vectors    0.18.3           r341h470a237_0    bioconda
bioconductor-xcms         1.50.1                 r3.4.1_0    bioconda
bioconductor-zlibbioc     1.26.0           r341h470a237_0    bioconda
[...]
libnetcdf                 4.3.3.1                       3    https://repo.anaconda.com/pkgs/free
[...]
python                    3.6.5                         1    conda-forge
[...]
r                         3.4.1                  r3.4.1_0    conda-forge
[...]
r-base                    3.4.1                         4    conda-forge
[...]