Question: I am attempting to create a conda environment with 3 packages and a specific python version and get the following output: $ conda create -n testing_junk -y instrain awscli samtools python=3.8 Collecting package metadata (current_repodata.json): done Solving environment: failed with repodata from current_repodata.json, will retry with next repodata source. Collecting package metadata (repodata.json): done Solving environment: | Found conflicts! Looking for incompatible packages. This can take several minutes. Press CTRL-C to abort. failed \ UnsatisfiableError: The following specifications were found to be incompatible with each other: Output in format: Requested package -> Available versions Package ncurses conflicts for: python=3.8 -> ncurses[version='>=6.1,<6.2.0a0|>=6.2,<7.0a0|>=6.1,<7.0a0'] awscli -> python[version='>=3.8,<3.9.0a0'] -> ncurses[version='5.9.*|5.9|>=6.1,<6.2.0a0|>=6.2,<7.0a0|>=6.1,<7.0a0|>=6.0,<7.0a0|6.0.*'] instrain -> python[version='>=3.4'] -> ncurses[version='5.9.*|5.9|>=6.1,<6.2.0a0|>=6.2,<7.0a0|>=6.1,<7.0a0|>=6.0,<7.0a0|6.0.*'] python=3.8 -> readline[version='>=7.0,<8.0a0'] -> ncurses[version='5.9.*|>=6.0,<7.0a0|6.0.*'] samtools -> ncurses[version='5.9|5.9.*|>=5.9,<5.10.0a0|>=6.1,<6.2.0a0'] Package python conflicts for: awscli -> python[version='2.7.*|3.5.*|3.6.*|>=2.7,<2.8.0a0|>=3.6,<3.7.0a0|>=3.7,<3.8.0a0|>=3.8,<3.9.0a0|>=3.5,<3.6.0a0|3.4.*'] python=3.8 instrain -> biopython -> python[version='2.7.*|3.5.*|3.6.*|>=2.7,<2.8.0a0|>=3.6,<3.7.0a0|>=3.8,<3.9.0a0|>=3.7,<3.8.0a0|>=3.5,<3.6.0a0|3.4.*|>3|>=3.5|<3.0.0|>=3.6'] instrain -> python[version='>=3.4'] awscli -> python_abi=3.8[build=*_cp38] -> python[version='3.7.*|3.8.*'] Package ca-certificates conflicts for: samtools -> openssl[version='>=1.1.1a,<1.1.2a'] -> ca-certificates python=3.8 -> openssl[version='>=1.1.1g,<1.1.2a'] -> ca-certificates awscli -> python[version='>=2.7,<2.8.0a0'] -> ca-certificates Package setuptools conflicts for: python=3.8 -> pip -> setuptools instrain -> matplotlib-base -> setuptools[version='>=40.0'] Package libgcc-ng conflicts for: samtools -> ncurses[version='>=6.1,<6.2.0a0'] -> libgcc-ng[version='>=7.2.0'] samtools -> libgcc-ng[version='>=4.9|>=7.3.0'] Package pypy3.6 conflicts for: instrain -> numpy -> pypy3.6[version='7.3.0.*|7.3.1.*|>=7.3.1'] awscli -> python[version='>=3.6,<3.7.0a0'] -> pypy3.6[version='7.3.*|7.3.0.*|7.3.1.*'] Package bzip2 conflicts for: samtools -> bzip2[version='1.0.*|>=1.0.6,<2.0a0|>=1.0.8,<2.0a0'] instrain -> pysam -> bzip2[version='>=1.0.6,<2.0a0|>=1.0.8,<2.0a0'] awscli -> python[version='>=3.7,<3.8.0a0'] -> bzip2[version='>=1.0.6,<2.0a0|>=1.0.8,<2.0a0'] Package zlib conflicts for: samtools -> zlib[version='1.2.11.*|>=1.2.11,<1.3.0a0|1.2.8.*|1.2.8'] samtools -> curl[version='>=7.59.0,<8.0a0'] -> zlib[version='1.2.*|1.2.11'] Package samtools conflicts for: samtools instrain -> pysam -> samtools[version='1.3|1.3.1.*|1.3.1|1.5.*|1.6.*|1.7|1.7.*|1.9.*|>=1.4.1|>=1.4.1,<1.5|>=1.4,<1.5|>=1.3,<1.4|>=1.3'] Package openssl conflicts for: samtools -> curl[version='>=7.59.0,<8.0a0'] -> openssl[version='1.0.*|>=1.0.2o,<1.0.3a|>=1.0.2m,<1.0.3a'] samtools -> openssl[version='>=1.0.2p,<1.0.3a|>=1.0.2r,<1.0.3a|>=1.1.1a,<1.1.2a'] Package _libgcc_mutex conflicts for: samtools -> libgcc-ng[version='>=7.3.0'] -> _libgcc_mutex[version='*|0.1',build='main|conda_forge'] python=3.8 -> libgcc-ng[version='>=7.5.0'] -> _libgcc_mutex[version='*|0.1',build='main|conda_forge']The following specifications were found to be incompatible with your CUDA driver: - feature:/linux-64::__cuda==10.2=0 - feature:|@/linux-64::__cuda==10.2=0 Your installed CUDA driver is: 10.2  I understand that there is something about the packages that conflict with each other, but I'm unable to interpret this output to understand what the problem is.  For example, in looking at the first block of conflicts (related to ncurses), shouldn't version 6.1 satisfy all requirements listed? Additionally, for the block about package setuptools, I don't see any problem at all? Any insight into how to interpret these conflicts so that I can attempt to address them would be much appreciated.

Answer: Some Practical Advice @Quantum7's answer gives a fine literal interpretation of Conda's conflict reporting. However, I wanted to offer a more practical take, which is that this "feature" from Conda is too non-specific to be useful in most non-trivial environments. And sometimes it won't even include the underlying conflict. Don't waste your time with it! Conda's Conflict Reporting is Often Not Helpful On the face of it, Conda attempts to report all possible sources of conflict. That is, all sets of paths in the dependency graph that begin from the explicit specifications and end in the same package. This amounts to most of what is reported being innocuous and frankly distracting. For example, the zlib "conflicts": Package zlib conflicts for: samtools -> zlib[version='1.2.11.*|>=1.2.11,<1.3.0a0|1.2.8.*|1.2.8'] samtools -> curl[version='>=7.59.0,<8.0a0'] -> zlib[version='1.2.*|1.2.11']  Since samtools depends on zlib both directly and indirectly (mediated through curl), this comes up as two alternate paths that lead to constraints. The problem is that the intersection of the final constraints are not empty, such that there is nothing incompatible here. Furthermore, there are cases where none of what is reported is in conflict (e.g., this question or this one), which means parsing through the output could be a complete waste of time. Try Mamba Instead, if one is actually concerned with resolving conflicts, I find Mamba to be more effective to work with, both in speed and precision. # install mamba conda install -n base conda-forge::mamba # use 'mamba' just like 'conda' mamba create -n foo instrain awscli samtools python=3.8  Unfortunately, this example simply works now. However, there are other questions where Conda and Mamba unsatisfiability reporting is compared, e.g., this question.